Plumb Fragment API between "public" and "browser" modules

The implementation code of the Fragment and the class actually extending
Fragment live in different ClassLoaders. Thus we need to forward calls
back and forth through aidl interfaces.

Change-Id: I765d116480778ce4d0c82dece91550c85855e950
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1813299Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Pavel Shmakov <pshmakov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699785}

weblayer/browser/java/BUILD.gn

@@ -8,6 +8,7 @@ import("//build/config/android/rules.gni")
 android_library("java") {
   java_files = [
     "org/chromium/weblayer_private/BrowserControllerImpl.java",
+    "org/chromium/weblayer_private/BrowserFragmentControllerImpl.java",
     "org/chromium/weblayer_private/BrowserObserverProxy.java",
     "org/chromium/weblayer_private/ContentView.java",
     "org/chromium/weblayer_private/ContentViewRenderView.java",
@@ -18,6 +19,7 @@ android_library("java") {
     "org/chromium/weblayer_private/TopControlsContainerView.java",
     "org/chromium/weblayer_private/WebLayerImpl.java",
     "org/chromium/weblayer_private/ChildProcessServiceImpl.java",
+    "org/chromium/weblayer_private/RemoteFragmentImpl.java",
   ]
 
   deps = [
@@ -54,6 +56,7 @@ android_library("client_java") {
 android_aidl("aidl") {
   import_include = [ "org/chromium/weblayer_private/aidl" ]
   sources = [
+    "org/chromium/weblayer_private/aidl/IBrowserFragmentController.aidl",
     "org/chromium/weblayer_private/aidl/IBrowserController.aidl",
     "org/chromium/weblayer_private/aidl/IBrowserControllerClient.aidl",
     "org/chromium/weblayer_private/aidl/IChildProcessService.aidl",
@@ -63,6 +66,8 @@ android_aidl("aidl") {
     "org/chromium/weblayer_private/aidl/INavigationControllerClient.aidl",
     "org/chromium/weblayer_private/aidl/IObjectWrapper.aidl",
     "org/chromium/weblayer_private/aidl/IProfile.aidl",
+    "org/chromium/weblayer_private/aidl/IRemoteFragment.aidl",
+    "org/chromium/weblayer_private/aidl/IRemoteFragmentClient.aidl",
     "org/chromium/weblayer_private/aidl/IWebLayer.aidl",
   ]
 }

weblayer/browser/java/org/chromium/weblayer_private/BrowserControllerImpl.java

@@ -29,8 +29,10 @@ import org.chromium.weblayer_private.aidl.ObjectWrapper;
 public final class BrowserControllerImpl extends IBrowserController.Stub {
     private long mNativeBrowserController;
 
+    // TODO: move mWindowAndroid, mContentViewRenderView, mContentView, mTopControlsContainerView to
+    // BrowserFragmentControllerImpl.
     private ActivityWindowAndroid mWindowAndroid;
-    // This view is the main view (returned from OnCreateView()).
+    // This view is the main view (returned from the fragment's onCreateView()).
     private ContentViewRenderView mContentViewRenderView;
     // One of these is needed per WebContents.
     private ContentView mContentView;
@@ -125,7 +127,6 @@ public final class BrowserControllerImpl extends IBrowserController.Stub {
         mBrowserObserverProxy = new BrowserObserverProxy(mNativeBrowserController, client);
     }
 
-    @Override
     public void destroy() {
         BrowserControllerImplJni.get().setTopControlsContainerView(
                 mNativeBrowserController, BrowserControllerImpl.this, 0);
@@ -138,18 +139,16 @@ public final class BrowserControllerImpl extends IBrowserController.Stub {
         mNativeBrowserController = 0;
     }
 
-    @Override
     public void setTopView(IObjectWrapper viewWrapper) {
         View view = ObjectWrapper.unwrap(viewWrapper, View.class);
         mTopControlsContainerView.setView(view);
     }
 
-    @Override
-    public IObjectWrapper onCreateView() {
-        return ObjectWrapper.wrap(mContentViewRenderView);
+    /** Returns top-level View this Controller works with */
+    public View getView() {
+        return mContentViewRenderView;
     }
 
-    @Override
     public void setSupportsEmbedding(boolean enable, IObjectWrapper callback) {
         mContentViewRenderView.requestMode(enable ? ContentViewRenderView.MODE_TEXTURE_VIEW
                                                   : ContentViewRenderView.MODE_SURFACE_VIEW,

weblayer/browser/java/org/chromium/weblayer_private/BrowserFragmentControllerImpl.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private;
+
+import android.view.View;
+
+import org.chromium.weblayer_private.aidl.IBrowserController;
+import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
+import org.chromium.weblayer_private.aidl.IObjectWrapper;
+import org.chromium.weblayer_private.aidl.IRemoteFragment;
+import org.chromium.weblayer_private.aidl.IRemoteFragmentClient;
+
+/**
+ * Implementation of {@link IBrowserFragmentController}.
+ */
+public class BrowserFragmentControllerImpl extends IBrowserFragmentController.Stub {
+    private final BrowserControllerImpl mController;
+    private final BrowserRemoteFragmentImpl mRemoteFragmentImpl;
+
+    public BrowserFragmentControllerImpl(BrowserControllerImpl controller,
+            IRemoteFragmentClient fragmentClient) {
+        mController = controller;
+        mRemoteFragmentImpl = new BrowserRemoteFragmentImpl(fragmentClient);
+    }
+
+    @Override
+    public void setTopView(IObjectWrapper view) {
+        mController.setTopView(view);
+    }
+
+    @Override
+    public void setSupportsEmbedding(boolean enable, IObjectWrapper valueCallback) {
+        mController.setSupportsEmbedding(enable, valueCallback);
+    }
+
+    @Override
+    public IRemoteFragment getRemoteFragment() {
+        return mRemoteFragmentImpl;
+    }
+
+    @Override
+    public IBrowserController getBrowserController() {
+        return mController;
+    }
+
+    @Override
+    public void destroy() {
+        mController.destroy();
+    }
+
+    private class BrowserRemoteFragmentImpl extends RemoteFragmentImpl {
+        public BrowserRemoteFragmentImpl(IRemoteFragmentClient client) {
+            super(client);
+        }
+
+        @Override
+        public View onCreateView() {
+            return mController.getView();
+        }
+    }
+}

weblayer/browser/java/org/chromium/weblayer_private/ProfileImpl.java

@@ -8,9 +8,10 @@ import android.content.Context;
 
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.NativeMethods;
-import org.chromium.weblayer_private.aidl.IBrowserController;
+import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
 import org.chromium.weblayer_private.aidl.IObjectWrapper;
 import org.chromium.weblayer_private.aidl.IProfile;
+import org.chromium.weblayer_private.aidl.IRemoteFragmentClient;
 import org.chromium.weblayer_private.aidl.ObjectWrapper;
 
 @JNINamespace("weblayer")
@@ -33,8 +34,12 @@ public final class ProfileImpl extends IProfile.Stub {
     }
 
     @Override
-    public IBrowserController createBrowserController(IObjectWrapper context) {
-        return new BrowserControllerImpl(ObjectWrapper.unwrap(context, Context.class), this);
+    public IBrowserFragmentController createBrowserFragmentController(IRemoteFragmentClient
+            fragmentClient,
+            IObjectWrapper context) {
+        BrowserControllerImpl browserController = new BrowserControllerImpl(
+                    ObjectWrapper.unwrap(context, Context.class), this);
+        return new BrowserFragmentControllerImpl(browserController, fragmentClient);
     }
 
     long getNativeProfile() {

weblayer/browser/java/org/chromium/weblayer_private/RemoteFragmentImpl.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private;
+
+import android.app.Activity;
+import android.content.Context;
+import android.os.Bundle;
+import android.os.RemoteException;
+import android.view.View;
+
+import org.chromium.weblayer_private.aidl.APICallException;
+import org.chromium.weblayer_private.aidl.IObjectWrapper;
+import org.chromium.weblayer_private.aidl.IRemoteFragment;
+import org.chromium.weblayer_private.aidl.IRemoteFragmentClient;
+import org.chromium.weblayer_private.aidl.ObjectWrapper;
+
+/**
+ * Base for the classes controlling a Fragment that exists in another ClassLoader. Extending this
+ * class is similar to extending Fragment: e.g. one can override lifecycle methods, not forgetting
+ * to call super, etc.
+ */
+public abstract class RemoteFragmentImpl extends IRemoteFragment.Stub {
+    private final IRemoteFragmentClient mClient;
+
+    protected RemoteFragmentImpl(IRemoteFragmentClient client) {
+        mClient = client;
+    }
+
+    public View onCreateView() {
+        return null;
+    }
+
+    public final Activity getActivity() {
+        try {
+            return ObjectWrapper.unwrap(mClient.getActivity(), Activity.class);
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    // TODO(pshmakov): add dependency to androidx.annotation and put @CallSuper here.
+    public void onCreate(Bundle savedInstanceState) {
+        try {
+            mClient.superOnCreate(ObjectWrapper.wrap(savedInstanceState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onAttach(Context context) {
+        try {
+            mClient.superOnAttach(ObjectWrapper.wrap(context));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onActivityCreated(Bundle savedInstanceState) {
+        try {
+            mClient.superOnActivityCreated(ObjectWrapper.wrap(savedInstanceState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onStart() {
+        try {
+            mClient.superOnStart();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onDestroy() {
+        try {
+            mClient.superOnDestroy();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onDetach() {
+        try {
+            mClient.superOnDetach();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onResume() {
+        try {
+            mClient.superOnResume();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onDestroyView() {
+        try {
+            mClient.superOnDestroyView();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onStop() {
+        try {
+            mClient.superOnStop();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onPause() {
+        try {
+            mClient.superOnPause();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    public void onSaveInstaceState(Bundle outState) {
+        try {
+            mClient.superOnSaveInstanceState(ObjectWrapper.wrap(outState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    // IRemoteFragment implementation below.
+
+    @Override
+    public final IObjectWrapper handleOnCreateView() {
+        return ObjectWrapper.wrap(onCreateView());
+    }
+
+    @Override
+    public final void handleOnStart() {
+        onStart();
+    }
+
+    @Override
+    public final void handleOnCreate(IObjectWrapper savedInstanceState) {
+        onCreate(ObjectWrapper.unwrap(savedInstanceState, Bundle.class));
+    }
+
+    @Override
+    public final void handleOnAttach(IObjectWrapper context) {
+        onAttach(ObjectWrapper.unwrap(context, Context.class));
+    }
+
+    @Override
+    public final void handleOnActivityCreated(IObjectWrapper savedInstanceState) {
+        onActivityCreated(ObjectWrapper.unwrap(savedInstanceState, Bundle.class));
+    }
+
+    @Override
+    public final void handleOnResume()  {
+        onResume();
+    }
+
+    @Override
+    public final void handleOnPause()  {
+        onPause();
+    }
+
+    @Override
+    public final void handleOnStop()  {
+        onStop();
+    }
+
+    @Override
+    public final void handleOnDestroyView()  {
+        onDestroyView();
+    }
+
+    @Override
+    public final void handleOnDetach()  {
+        onDetach();
+    }
+
+    @Override
+    public final void handleOnDestroy()  {
+        onDestroy();
+    }
+
+    @Override
+    public final void handleOnSaveInstanceState(IObjectWrapper outState)  {
+        onSaveInstaceState(ObjectWrapper.unwrap(outState, Bundle.class));
+    }
+}

weblayer/browser/java/org/chromium/weblayer_private/aidl/IBrowserController.aidl

@@ -5,21 +5,11 @@
 package org.chromium.weblayer_private.aidl;
 
 import org.chromium.weblayer_private.aidl.IBrowserControllerClient;
-import org.chromium.weblayer_private.aidl.IObjectWrapper;
+import org.chromium.weblayer_private.aidl.INavigationController;
+import org.chromium.weblayer_private.aidl.INavigationControllerClient;
 
 interface IBrowserController {
   void setClient(in IBrowserControllerClient client) = 0;
 
   INavigationController createNavigationController(in INavigationControllerClient client) = 1;
-
-  void setTopView(in IObjectWrapper view) = 2;
-
-  void destroy() = 3;
-
-  IObjectWrapper onCreateView() = 4;
-
-  // |valueCallback| is a wrapped ValueCallback<Boolean> instead. The bool value in |valueCallback|
-  // indicates is whether the request was successful. Request might fail if it is subsumed by a
-  // following request, or if this object is destroyed.
-  void setSupportsEmbedding(in boolean enable, in IObjectWrapper valueCallback) = 5;
 }

weblayer/browser/java/org/chromium/weblayer_private/aidl/IBrowserFragmentController.aidl

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private.aidl;
+
+import org.chromium.weblayer_private.aidl.IBrowserController;
+import org.chromium.weblayer_private.aidl.IObjectWrapper;
+import org.chromium.weblayer_private.aidl.IRemoteFragment;
+
+interface IBrowserFragmentController {
+  void destroy() = 0;
+  IBrowserController getBrowserController() = 1;
+  IRemoteFragment getRemoteFragment() = 2;
+  void setTopView(IObjectWrapper view) = 3;
+
+  // |valueCallback| is a wrapped ValueCallback<Boolean> instead. The bool value in |valueCallback|
+  // indicates is whether the request was successful. Request might fail if it is subsumed by a
+  // following request, or if this object is destroyed.
+  void setSupportsEmbedding(in boolean enable, in IObjectWrapper valueCallback) = 4;
+}

weblayer/browser/java/org/chromium/weblayer_private/aidl/IProfile.aidl

@@ -4,7 +4,8 @@
 
 package org.chromium.weblayer_private.aidl;
 
-import org.chromium.weblayer_private.aidl.IBrowserController;
+import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
+import org.chromium.weblayer_private.aidl.IRemoteFragmentClient;
 import org.chromium.weblayer_private.aidl.IObjectWrapper;
 
 interface IProfile {
@@ -13,8 +14,11 @@ interface IProfile {
   void clearBrowsingData() = 1;
 
   /**
-   * Creates a new IBrowserController.
+   * Creates a new IBrowserFragmentController.
+   * @param fragmentClient IRemoteFragmentClient that will host the Fragment implemented on the
+   * weblayer side.
    * @param context Context that refers the the weblayer implementation
    */
-  IBrowserController createBrowserController(in IObjectWrapper context) = 2;
+  IBrowserFragmentController createBrowserFragmentController(
+          in IRemoteFragmentClient fragmentClient, in IObjectWrapper context) = 2;
 }

weblayer/browser/java/org/chromium/weblayer_private/aidl/IRemoteFragment.aidl

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private.aidl;
+
+import org.chromium.weblayer_private.aidl.IObjectWrapper;
+
+interface IRemoteFragment {
+  // Using IObjectWrapper instead of Bundle to pass by reference instead of by value.
+  void handleOnCreate(in IObjectWrapper savedInstanceState) = 0;
+  void handleOnAttach(in IObjectWrapper context) = 1;
+  void handleOnActivityCreated(in IObjectWrapper savedInstanceState) = 2;
+  IObjectWrapper handleOnCreateView() = 3;
+  void handleOnStart() = 4;
+  void handleOnResume() = 5;
+  void handleOnPause() = 6;
+  void handleOnStop() = 7;
+  void handleOnDestroyView() = 8;
+  void handleOnDetach() = 9;
+  void handleOnDestroy() = 10;
+  void handleOnSaveInstanceState(in IObjectWrapper outState) = 11;
+}

weblayer/browser/java/org/chromium/weblayer_private/aidl/IRemoteFragmentClient.aidl

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private.aidl;
+
+interface IRemoteFragmentClient {
+  void superOnCreate(in IObjectWrapper savedInstanceState) = 0;
+  void superOnAttach(in IObjectWrapper context) = 1;
+  void superOnActivityCreated(in IObjectWrapper savedInstanceState) = 2;
+  void superOnStart() = 3;
+  void superOnResume() = 4;
+  void superOnPause() = 5;
+  void superOnStop() = 6;
+  void superOnDestroyView() = 7;
+  void superOnDetach() = 8;
+  void superOnDestroy() = 9;
+  void superOnSaveInstanceState(in IObjectWrapper outState) = 10;
+
+  IObjectWrapper getActivity() = 11;
+}

weblayer/public/java/BUILD.gn

@@ -21,8 +21,9 @@ android_resources("client_resources") {
 
 android_library("java") {
   java_files = [
+    "org/chromium/weblayer/RemoteFragmentClient.java",
     "org/chromium/weblayer/BrowserController.java",
-    "org/chromium/weblayer/BrowserFragmentImpl.java",
+    "org/chromium/weblayer/BrowserFragmentController.java",
     "org/chromium/weblayer/BrowserObserver.java",
     "org/chromium/weblayer/Callback.java",
     "org/chromium/weblayer/ListenableResult.java",
@@ -38,6 +39,10 @@ android_library("java") {
   deps = [
     ":client_resources",
     "//weblayer/browser/java:client_java",
+
+    # TODO(pshmakov): Exclude this from the artifact and make sure we can depend on other version
+    # than Chrome.
+    "//third_party/android_deps:android_support_v4_java",
   ]
 
   # Needed for android.webkit.WebViewDelegate.

weblayer/public/java/org/chromium/weblayer/BrowserController.java

@@ -6,12 +6,10 @@ package org.chromium.weblayer;
 
 import android.net.Uri;
 import android.os.RemoteException;
-import android.view.View;
 
 import org.chromium.weblayer_private.aidl.APICallException;
 import org.chromium.weblayer_private.aidl.IBrowserController;
 import org.chromium.weblayer_private.aidl.IBrowserControllerClient;
-import org.chromium.weblayer_private.aidl.ObjectWrapper;
 
 public final class BrowserController {
     private final IBrowserController mImpl;
@@ -47,23 +45,6 @@ public final class BrowserController {
         mObservers.removeObserver(observer);
     }
 
-    // Only called from BrowserFragmentImpl.
-    void destroy() {
-        try {
-            mImpl.destroy();
-        } catch (RemoteException e) {
-            throw new APICallException(e);
-        }
-    }
-
-    public View onCreateView() {
-        try {
-            return ObjectWrapper.unwrap(mImpl.onCreateView(), View.class);
-        } catch (RemoteException e) {
-            throw new APICallException(e);
-        }
-    }
-
     IBrowserController getIBrowserController() {
         return mImpl;
     }

weblayer/public/java/org/chromium/weblayer/BrowserFragmentImpl.java → weblayer/public/java/org/chromium/weblayer/BrowserFragmentController.java

@@ -5,43 +5,54 @@
 package org.chromium.weblayer;
 
 import android.os.RemoteException;
+import android.support.v4.app.Fragment;
 import android.view.View;
 import android.webkit.ValueCallback;
 
 import org.chromium.weblayer_private.aidl.APICallException;
-import org.chromium.weblayer_private.aidl.IBrowserController;
+import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
 import org.chromium.weblayer_private.aidl.ObjectWrapper;
 
 /**
- * Provides an API similar to that of Fragment. To avoid depending upon a particular Fragment
- * implementation, this class does not actually extend Fragment. It is expected that consumers of
- * this provide an implementation of Fragment that calls through to the similarly named methods in
- * this class.
- *
- * BrowserFragmentImpl is created from Profile.
+ * Represents a browser fragment. Created from Profile.
  */
-public final class BrowserFragmentImpl {
-    private BrowserController mBrowserController;
+public final class BrowserFragmentController {
+    private final IBrowserFragmentController mImpl;
+    private final RemoteFragmentClient mFragment;
+    private BrowserController mController;
 
-    BrowserFragmentImpl(IBrowserController iBrowserController) {
-        mBrowserController = new BrowserController(iBrowserController);
+    BrowserFragmentController(IBrowserFragmentController impl, RemoteFragmentClient fragment) {
+        mImpl = impl;
+        mFragment = fragment;
     }
 
     public void destroy() {
-        mBrowserController.destroy();
-    }
-
-    public void setTopView(View view) {
         try {
-            getIBrowserController().setTopView(ObjectWrapper.wrap(view));
+            mImpl.destroy();
         } catch (RemoteException e) {
             throw new APICallException(e);
         }
     }
 
-    public View onCreateView() {
+    // TODO(pshmakov): rename this to BrowserTabController.
+    public BrowserController getBrowserController() {
+        if (mController == null) {
+            try {
+                mController = new BrowserController(mImpl.getBrowserController());
+            } catch (RemoteException e) {
+                throw new APICallException(e);
+            }
+        }
+        return mController;
+    }
+
+    public Fragment getFragment() {
+        return mFragment;
+    }
+
+    public void setTopView(View view) {
         try {
-            return ObjectWrapper.unwrap(getIBrowserController().onCreateView(), View.class);
+            mImpl.setTopView(ObjectWrapper.wrap(view));
         } catch (RemoteException e) {
             throw new APICallException(e);
         }
@@ -59,7 +70,7 @@ public final class BrowserFragmentImpl {
     public ListenableResult<Boolean> setSupportsEmbedding(boolean enable) {
         try {
             final ListenableResult<Boolean> listenableResult = new ListenableResult<Boolean>();
-            getIBrowserController().setSupportsEmbedding(
+            mImpl.setSupportsEmbedding(
                     enable, ObjectWrapper.wrap(new ValueCallback<Boolean>() {
                         @Override
                         public void onReceiveValue(Boolean result) {
@@ -71,12 +82,4 @@ public final class BrowserFragmentImpl {
             throw new APICallException(e);
         }
     }
-
-    public BrowserController getBrowserController() {
-        return mBrowserController;
-    }
-
-    private IBrowserController getIBrowserController() {
-        return mBrowserController.getIBrowserController();
-    }
 }

weblayer/public/java/org/chromium/weblayer/Profile.java

@@ -8,6 +8,7 @@ import android.content.Context;
 import android.os.RemoteException;
 
 import org.chromium.weblayer_private.aidl.APICallException;
+import org.chromium.weblayer_private.aidl.IBrowserFragmentController;
 import org.chromium.weblayer_private.aidl.IProfile;
 import org.chromium.weblayer_private.aidl.ObjectWrapper;
 
@@ -43,10 +44,14 @@ public final class Profile {
         }
     }
 
-    public BrowserFragmentImpl createBrowserFragment(Context context) {
+    public BrowserFragmentController createBrowserFragmentController(Context context) {
         try {
-            return new BrowserFragmentImpl(mImpl.createBrowserController(
-                    ObjectWrapper.wrap(WebLayer.createRemoteContext(context))));
+            RemoteFragmentClient fragmentClient = new RemoteFragmentClient();
+            IBrowserFragmentController browserFragmentImpl = mImpl.createBrowserFragmentController(
+                    fragmentClient.asIRemoteFragmentClient(),
+                    ObjectWrapper.wrap(WebLayer.createRemoteContext(context)));
+            fragmentClient.setRemoteFragment(browserFragmentImpl.getRemoteFragment());
+            return new BrowserFragmentController(browserFragmentImpl, fragmentClient);
         } catch (RemoteException e) {
             throw new APICallException(e);
         }

weblayer/public/java/org/chromium/weblayer/RemoteFragmentClient.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.os.RemoteException;
+import android.support.v4.app.Fragment;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.weblayer_private.aidl.APICallException;
+import org.chromium.weblayer_private.aidl.IObjectWrapper;
+import org.chromium.weblayer_private.aidl.IRemoteFragment;
+import org.chromium.weblayer_private.aidl.IRemoteFragmentClient;
+import org.chromium.weblayer_private.aidl.ObjectWrapper;
+
+/**
+ * Hosts a "remote fragment" (represented by {@link IRemoteFragment}) that lives in another
+ * ClassLoader. The remote fragment has all the actual logic (e.g. handling lifecycle events), while
+ * this class actually extends {@link Fragment}, forwarding the calls to and from the remote
+ * fragment. Thus it is "hosting" the fragment implemented elsewhere.
+ */
+public final class RemoteFragmentClient extends Fragment {
+    private final IRemoteFragmentClient mClientImpl = new IRemoteFragmentClient.Stub() {
+        @Override
+        public void superOnCreate(IObjectWrapper savedInstanceState) {
+            RemoteFragmentClient.super.onCreate(ObjectWrapper.unwrap(savedInstanceState,
+                    Bundle.class));
+        }
+
+        @Override
+        public void superOnAttach(IObjectWrapper context) {
+            RemoteFragmentClient.super.onAttach(ObjectWrapper.unwrap(context, Context.class));
+        }
+
+        @Override
+        public void superOnActivityCreated(IObjectWrapper savedInstanceState) {
+            RemoteFragmentClient.super.onCreate(ObjectWrapper.unwrap(savedInstanceState,
+                    Bundle.class));
+        }
+
+        @Override
+        public void superOnStart() {
+            RemoteFragmentClient.super.onStart();
+        }
+
+        @Override
+        public void superOnResume() {
+            RemoteFragmentClient.super.onResume();
+        }
+
+        @Override
+        public void superOnPause() {
+            RemoteFragmentClient.super.onPause();
+        }
+
+        @Override
+        public void superOnStop() {
+            RemoteFragmentClient.super.onStop();
+        }
+
+        @Override
+        public void superOnDestroyView() {
+            RemoteFragmentClient.super.onDestroyView();
+        }
+
+        @Override
+        public void superOnDetach() {
+            RemoteFragmentClient.super.onDetach();
+        }
+
+        @Override
+        public void superOnDestroy() {
+            RemoteFragmentClient.super.onDestroy();
+        }
+
+        @Override
+        public void superOnSaveInstanceState(IObjectWrapper outState) {
+            RemoteFragmentClient.super.onSaveInstanceState(ObjectWrapper.unwrap(outState,
+                    Bundle.class));
+        }
+
+        @Override
+        public IObjectWrapper getActivity() {
+            return ObjectWrapper.wrap(RemoteFragmentClient.this.getActivity());
+        }
+    };
+
+    private IRemoteFragment mRemoteFragment;
+
+    // TODO(pshmakov): how do we deal with FragmentManager restoring this Fragment on its own?
+    /* package */ void setRemoteFragment(IRemoteFragment remoteFragment) {
+        mRemoteFragment = remoteFragment;
+    }
+
+    /* package */ IRemoteFragmentClient asIRemoteFragmentClient() {
+        return mClientImpl;
+    }
+
+    @Override
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+            Bundle savedInstanceState) {
+        try {
+            return ObjectWrapper.unwrap(mRemoteFragment.handleOnCreateView(), View.class);
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onAttach(Context context) {
+        try {
+            mRemoteFragment.handleOnAttach(ObjectWrapper.wrap(context));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        try {
+            mRemoteFragment.handleOnCreate(ObjectWrapper.wrap(savedInstanceState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onActivityCreated(Bundle savedInstanceState) {
+        try {
+            mRemoteFragment.handleOnActivityCreated(ObjectWrapper.wrap(savedInstanceState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onStart() {
+        try {
+            mRemoteFragment.handleOnStart();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onResume() {
+        try {
+            mRemoteFragment.handleOnResume();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        try {
+            mRemoteFragment.handleOnSaveInstanceState(ObjectWrapper.wrap(outState));
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onPause() {
+        try {
+            mRemoteFragment.handleOnPause();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onStop() {
+        try {
+            mRemoteFragment.handleOnStop();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onDestroyView() {
+        try {
+            mRemoteFragment.handleOnDestroyView();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onDestroy() {
+        try {
+            mRemoteFragment.handleOnDestroy();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+
+    @SuppressWarnings("MissingSuperCall")
+    @Override
+    public void onDetach() {
+        try {
+            mRemoteFragment.handleOnDetach();
+        } catch (RemoteException e) {
+            throw new APICallException(e);
+        }
+    }
+}

weblayer/shell/android/demo_apk/src/org/chromium/weblayer/demo/WebLayerAnimationDemoActivity.java

@@ -7,15 +7,12 @@ package org.chromium.weblayer.demo;
 import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.app.FragmentTransaction;
 import android.text.InputType;
 import android.view.KeyEvent;
-import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewGroup;
 import android.view.inputmethod.EditorInfo;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
@@ -26,7 +23,7 @@ import android.widget.TextView;
 import android.widget.TextView.OnEditorActionListener;
 
 import org.chromium.weblayer.BrowserController;
-import org.chromium.weblayer.BrowserFragmentImpl;
+import org.chromium.weblayer.BrowserFragmentController;
 import org.chromium.weblayer.BrowserObserver;
 import org.chromium.weblayer.Profile;
 import org.chromium.weblayer.WebLayer;
@@ -40,38 +37,26 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
     private static final boolean USE_WEBVIEW = false;
 
     private Profile mProfile;
-    private final BrowserFragmentImpl mBrowserFragments[] = new BrowserFragmentImpl[4];
+    private final BrowserFragmentController mBrowserFragmentControllers[] =
+            new BrowserFragmentController[4];
     private final ContainerFrameLayout mContainerViews[] = new ContainerFrameLayout[4];
     private final MyWebView mWebViews[] = new MyWebView[4];
     private FrameLayout mMainView;
 
-    public static class ShellFragment extends Fragment {
-        private BrowserFragmentImpl mBrowserFragment;
-
-        ShellFragment(BrowserFragmentImpl browserFragment) {
-            mBrowserFragment = browserFragment;
-        }
-
-        @Override
-        public View onCreateView(
-                LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-            return mBrowserFragment.onCreateView();
-        }
-    }
-
     public static class ContainerFrameLayout extends FrameLayout {
-        private final BrowserFragmentImpl mFragment;
+        private final BrowserFragmentController mFragmentController;
         private int mIndex;
         private boolean mInterceptTouchEvent;
 
-        public ContainerFrameLayout(Context context, BrowserFragmentImpl fragment, int index) {
+        public ContainerFrameLayout(Context context, BrowserFragmentController fragmentController,
+                int index) {
             super(context);
-            mFragment = fragment;
+            mFragmentController = fragmentController;
             mIndex = index;
         }
 
-        public BrowserFragmentImpl getFragment() {
-            return mFragment;
+        public BrowserFragmentController getFragmentController() {
+            return mFragmentController;
         }
 
         public void setInterceptTouchEvent(boolean intercept) {
@@ -130,18 +115,20 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
     }
 
     private void createNewFragment(int index) {
-        mBrowserFragments[index] = mProfile.createBrowserFragment(this);
-        final BrowserController controller = mBrowserFragments[index].getBrowserController();
+        mBrowserFragmentControllers[index] = mProfile.createBrowserFragmentController(this);
+        final BrowserController controller = mBrowserFragmentControllers[index]
+                .getBrowserController();
 
         ContainerFrameLayout container =
-                new ContainerFrameLayout(this, mBrowserFragments[index], index);
+                new ContainerFrameLayout(this, mBrowserFragmentControllers[index],
+                        index);
         mContainerViews[index] = container;
         int viewId = View.generateViewId();
         container.setId(viewId);
         mMainView.addView(container);
 
         FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
-        transaction.add(viewId, new ShellFragment(mBrowserFragments[index]));
+        transaction.add(viewId, mBrowserFragmentControllers[index].getFragment());
         transaction.commit();
 
         EditText urlView = new EditText(this);
@@ -164,7 +151,7 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
                 return true;
             }
         });
-        mBrowserFragments[index].setTopView(urlView);
+        mBrowserFragmentControllers[index].setTopView(urlView);
 
         controller.addObserver(new BrowserObserver() {
             @Override
@@ -216,21 +203,21 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
             createNewFragment(1);
             createNewFragment(2);
 
-            mBrowserFragments[0].getBrowserController().getNavigationController().navigate(
-                    Uri.parse(sanitizeUrl("https://www.google.com")));
-            mBrowserFragments[1].getBrowserController().getNavigationController().navigate(
-                    Uri.parse(sanitizeUrl("https://en.wikipedia.org")));
-            mBrowserFragments[2].getBrowserController().getNavigationController().navigate(
-                    Uri.parse(sanitizeUrl("https://www.chromium.org")));
+            mBrowserFragmentControllers[0].getBrowserController().getNavigationController()
+                    .navigate(Uri.parse(sanitizeUrl("https://www.google.com")));
+            mBrowserFragmentControllers[1].getBrowserController().getNavigationController()
+                    .navigate(Uri.parse(sanitizeUrl("https://en.wikipedia.org")));
+            mBrowserFragmentControllers[2].getBrowserController().getNavigationController()
+                    .navigate(Uri.parse(sanitizeUrl("https://www.chromium.org")));
         }
     }
 
     @Override
     protected void onDestroy() {
-        for (int i = 0; i < mBrowserFragments.length; ++i) {
-            BrowserFragmentImpl fragment = mBrowserFragments[i];
+        for (int i = 0; i < mBrowserFragmentControllers.length; ++i) {
+            BrowserFragmentController fragment = mBrowserFragmentControllers[i];
             if (fragment != null) fragment.destroy();
-            mBrowserFragments[i] = null;
+            mBrowserFragmentControllers[i] = null;
         }
         if (mProfile != null) mProfile.destroy();
         super.onDestroy();
@@ -260,11 +247,11 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
             mContainerViews[1].setOnClickListener(new OnClickImpl());
             mContainerViews[2].setOnClickListener(new OnClickImpl());
             mContainerViews[0].post(() -> {
-                mBrowserFragments[0].setSupportsEmbedding(true).addCallback(
+                mBrowserFragmentControllers[0].setSupportsEmbedding(true).addCallback(
                         (Boolean result) -> animateDown(mContainerViews[0]));
-                mBrowserFragments[1].setSupportsEmbedding(true).addCallback(
+                mBrowserFragmentControllers[1].setSupportsEmbedding(true).addCallback(
                         (Boolean result) -> animateDown(mContainerViews[1]));
-                mBrowserFragments[2].setSupportsEmbedding(true).addCallback(
+                mBrowserFragmentControllers[2].setSupportsEmbedding(true).addCallback(
                         (Boolean result) -> animateDown(mContainerViews[2]));
             });
         }
@@ -310,17 +297,18 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
     private static void animateDown(ContainerFrameLayout container) {
         // Start animation after fullying switched from SurfaceView to TextureView.
         int index = container.getIndex();
-        container.getFragment().setSupportsEmbedding(true).addCallback((Boolean result) -> {
-            container.animate()
-                    .scaleX(1.0f / 3)
-                    .scaleY(1.0f / 3)
-                    .translationX(
-                            -container.getWidth() / 3.0f + (container.getWidth() / 3.0f * index))
-                    .translationY(container.getHeight() / 3.0f)
-                    .alpha(0.8f)
-                    .setDuration(500);
-            container.setInterceptTouchEvent(true);
-        });
+        container.getFragmentController().setSupportsEmbedding(true)
+                .addCallback((Boolean result) -> {
+                    container.animate()
+                            .scaleX(1.0f / 3)
+                            .scaleY(1.0f / 3)
+                            .translationX(-container.getWidth() / 3.0f
+                                    + (container.getWidth() / 3.0f * index))
+                            .translationY(container.getHeight() / 3.0f)
+                            .alpha(0.8f)
+                            .setDuration(500);
+                    container.setInterceptTouchEvent(true);
+                });
     }
 
     private static void animateUp(ContainerFrameLayout container) {
@@ -332,7 +320,7 @@ public class WebLayerAnimationDemoActivity extends FragmentActivity {
                 .alpha(1.0f)
                 .setDuration(500)
                 .withEndAction(() -> {
-                    container.getFragment().setSupportsEmbedding(false);
+                    container.getFragmentController().setSupportsEmbedding(false);
                     container.setInterceptTouchEvent(false);
                 });
     }

weblayer/shell/android/javatests/src/org/chromium/weblayer/test/RenderingTest.java

@@ -32,11 +32,11 @@ public class RenderingTest {
         String url = "data:text,foo";
 
         TestThreadUtils.runOnUiThreadBlocking(() -> {
-            activity.getBrowserFragmentImpl().setSupportsEmbedding(true).addCallback(
+            activity.getBrowserFragmentController().setSupportsEmbedding(true).addCallback(
                     (Boolean result) -> {
                         Assert.assertTrue(result);
-                        activity.getBrowserFragmentImpl().setSupportsEmbedding(false).addCallback(
-                                (Boolean result2) -> {
+                        activity.getBrowserFragmentController().setSupportsEmbedding(false)
+                                .addCallback((Boolean result2) -> {
                                     Assert.assertTrue(result2);
                                     mActivityTestRule.loadUrl(url);
                                     latch.countDown();
@@ -61,12 +61,12 @@ public class RenderingTest {
         CountDownLatch latch = new CountDownLatch(2);
         String url = "data:text,foo";
         TestThreadUtils.runOnUiThreadBlocking(() -> {
-            activity.getBrowserFragmentImpl().setSupportsEmbedding(true).addCallback(
+            activity.getBrowserFragmentController().setSupportsEmbedding(true).addCallback(
                     (Boolean result) -> {
                         Assert.assertTrue(result);
                         latch.countDown();
                     });
-            activity.getBrowserFragmentImpl().setSupportsEmbedding(true).addCallback(
+            activity.getBrowserFragmentController().setSupportsEmbedding(true).addCallback(
                     (Boolean result) -> {
                         Assert.assertTrue(result);
                         latch.countDown();

weblayer/shell/android/javatests/src/org/chromium/weblayer/test/SmokeTest.java

@@ -28,11 +28,14 @@ public class SmokeTest {
         WebLayerShellActivity activity = mActivityTestRule.launchShellWithUrl("about:blank");
         Assert.assertNotNull(activity);
 
+        TestThreadUtils.runOnUiThreadBlocking(
+                () -> { activity.getBrowserFragmentController().setSupportsEmbedding(true); });
+
         CountDownLatch latch = new CountDownLatch(1);
         String url = "data:text,foo";
 
         TestThreadUtils.runOnUiThreadBlocking(() -> {
-            activity.getBrowserFragmentImpl().setSupportsEmbedding(true).addCallback(
+            activity.getBrowserFragmentController().setSupportsEmbedding(true).addCallback(
                     (Boolean result) -> {
                         Assert.assertTrue(result);
                         mActivityTestRule.loadUrl(url);

weblayer/shell/android/shell_apk/src/org/chromium/weblayer/shell/WebLayerShellActivity.java

@@ -7,15 +7,12 @@ package org.chromium.weblayer.shell;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.app.FragmentTransaction;
 import android.text.InputType;
 import android.text.TextUtils;
 import android.view.KeyEvent;
-import android.view.LayoutInflater;
 import android.view.View;
-import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.view.inputmethod.EditorInfo;
 import android.widget.EditText;
@@ -26,7 +23,7 @@ import android.widget.TextView;
 import android.widget.TextView.OnEditorActionListener;
 
 import org.chromium.weblayer.BrowserController;
-import org.chromium.weblayer.BrowserFragmentImpl;
+import org.chromium.weblayer.BrowserFragmentController;
 import org.chromium.weblayer.BrowserObserver;
 import org.chromium.weblayer.Profile;
 import org.chromium.weblayer.WebLayer;
@@ -38,32 +35,18 @@ public class WebLayerShellActivity extends FragmentActivity {
     private static final String TAG = "WebLayerShell";
 
     private Profile mProfile;
-    private BrowserFragmentImpl mBrowserFragment;
+    private BrowserFragmentController mBrowserFragmentController;
     private BrowserController mBrowserController;
     private EditText mUrlView;
     private ProgressBar mLoadProgressBar;
     private View mMainView;
 
-    public static class ShellFragment extends Fragment {
-        private BrowserFragmentImpl mBrowserFragment;
-
-        ShellFragment(BrowserFragmentImpl browserFragment) {
-            mBrowserFragment = browserFragment;
-        }
-
-        @Override
-        public View onCreateView(
-                LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-            return mBrowserFragment.onCreateView();
-        }
-    }
-
     public BrowserController getBrowserController() {
         return mBrowserController;
     }
 
-    public BrowserFragmentImpl getBrowserFragmentImpl() {
-        return mBrowserFragment;
+    public BrowserFragmentController getBrowserFragmentController() {
+        return mBrowserFragmentController;
     }
 
     @Override
@@ -118,15 +101,16 @@ public class WebLayerShellActivity extends FragmentActivity {
         topContentsContainer.addView(mLoadProgressBar, progressLayoutParams);
 
         mProfile = WebLayer.getInstance().createProfile(null);
-        mBrowserFragment = mProfile.createBrowserFragment(this);
-        mBrowserController = mBrowserFragment.getBrowserController();
+
+        mBrowserFragmentController = mProfile.createBrowserFragmentController(this);
 
         FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
-        transaction.add(viewId, new ShellFragment(mBrowserFragment));
+        transaction.add(viewId, mBrowserFragmentController.getFragment());
         transaction.commit();
 
-        mBrowserFragment.setTopView(topContentsContainer);
+        mBrowserFragmentController.setTopView(topContentsContainer);
 
+        mBrowserController = mBrowserFragmentController.getBrowserController();
         String startupUrl = getUrlFromIntent(getIntent());
         if (TextUtils.isEmpty(startupUrl)) {
             startupUrl = "http://google.com";
@@ -154,7 +138,7 @@ public class WebLayerShellActivity extends FragmentActivity {
     @Override
     protected void onDestroy() {
         if (mProfile != null) mProfile.destroy();
-        if (mBrowserFragment != null) mBrowserFragment.destroy();
+        if (mBrowserFragmentController != null) mBrowserFragmentController.destroy();
         super.onDestroy();
     }