[remoteobjects] Add RemoteObjectGatewayProxy

This change adds an initial version of a class that establishes
the mojo connection with the renderer and calls
RemoteObjectGateway interface methods. Only the 'add interface'
functionality is implemented in this CL.

Bug: 794320
Test: local patch (https://crrev.com/c/2293476) where JavascriptInjectorImpl uses RemoteObjectGatewayProxy + JavaBridgeBasicsTest#testTypeOfInjectedObject test
Change-Id: I72c99bc1f9480197a9e90d216c20e0f422974adb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2285026
Commit-Queue: Oksana Zhuravlova <oksamyt@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Shimi Zhang <ctzsm@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792264}

content/public/android/BUILD.gn

@@ -238,6 +238,7 @@ android_library("content_java") {
     "java/src/org/chromium/content/browser/remoteobjects/RemoteObjectAuditorImpl.java",
     "java/src/org/chromium/content/browser/remoteobjects/RemoteObjectHostImpl.java",
     "java/src/org/chromium/content/browser/remoteobjects/RemoteObjectImpl.java",
+    "java/src/org/chromium/content/browser/remoteobjects/RemoteObjectInjector.java",
     "java/src/org/chromium/content/browser/remoteobjects/RemoteObjectRegistry.java",
     "java/src/org/chromium/content/browser/selection/AdditionalMenuItemProvider.java",
     "java/src/org/chromium/content/browser/selection/AdditionalMenuItemProviderImpl.java",

content/public/android/java/src/org/chromium/content/browser/remoteobjects/RemoteObjectHostImpl.java

@@ -54,6 +54,10 @@ class RemoteObjectHostImpl implements RemoteObjectHost {
         mRegistry = new WeakReference<>(registry);
     }
 
+    public RemoteObjectRegistry getRegistry() {
+        return mRegistry.get();
+    }
+
     @Override
     public void getObject(int objectId, InterfaceRequest<RemoteObject> request) {
         try (InterfaceRequest<RemoteObject> autoClose = request) {

content/public/android/java/src/org/chromium/content/browser/remoteobjects/RemoteObjectInjector.java

+// Copyright 2020 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.content.browser.remoteobjects;
+
+import org.chromium.blink.mojom.RemoteObjectGateway;
+import org.chromium.blink.mojom.RemoteObjectGatewayFactory;
+import org.chromium.content_public.browser.RenderFrameHost;
+import org.chromium.content_public.browser.WebContents;
+import org.chromium.content_public.browser.WebContentsObserver;
+import org.chromium.mojo.bindings.InterfaceRequest;
+import org.chromium.mojo.system.Pair;
+import org.chromium.mojo.system.impl.CoreImpl;
+
+import java.lang.annotation.Annotation;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Owned and constructed by JavascriptInjectorImpl.
+ * Could possibly be flattened into JavascriptInjectorImpl eventually, but may be nice to keep
+ * separate while there are separate codepaths.
+ */
+public final class RemoteObjectInjector extends WebContentsObserver {
+    /**
+     * Helper class for holding objects used to interact
+     * with the RemoteObjectGateway in the renderer.
+     */
+    private static class RemoteObjectGatewayHelper {
+        public RemoteObjectGateway.Proxy gateway;
+        public RemoteObjectHostImpl host;
+        public RemoteObjectGatewayHelper(
+                RemoteObjectGateway.Proxy newGateway, RemoteObjectHostImpl newHost) {
+            gateway = newGateway;
+            host = newHost;
+        }
+    }
+
+    private final Set<Object> mRetainingSet = new HashSet<>();
+    private final Map<String, Pair<Object, Class<? extends Annotation>>> mInjectedObjects =
+            new HashMap<>();
+    private final Map<RenderFrameHost, RemoteObjectGatewayHelper> mRemoteObjectGatewayHelpers =
+            new HashMap<>();
+
+    public RemoteObjectInjector(WebContents webContents) {
+        super(webContents);
+    }
+
+    @Override
+    public void renderFrameCreated(int renderProcessId, int renderFrameId) {
+        // TODO(crbug.com/1105935): replicate the necessary logic from
+        // GinJavaBridgeDispatcherHost::RenderFrameCreated().
+
+        // TODO(crbug.com/1107555): get the RenderFrameHost
+        // from renderProcessId and renderFrameId.
+    }
+
+    public void addInterface(Object object, String name) {
+        WebContents webContents = mWebContents.get();
+        if (webContents == null) return;
+
+        // TODO(crbug.com/1105935): find a way to make requiredAnnotation available to
+        // mRemoteObjectHost when JavascriptInjectorImpl calls addInterface().
+        Class<? extends Annotation> requiredAnnotation = null;
+        mInjectedObjects.put(name, new Pair<>(object, requiredAnnotation));
+
+        // TODO(crbug.com/1105935): the objects need to be injected into all frames, not just the
+        // main one.
+        addInterfaceForFrame(webContents.getMainFrame(), object, name, requiredAnnotation);
+    }
+
+    private void addInterfaceForFrame(RenderFrameHost frameHost, Object object, String name,
+            Class<? extends Annotation> requiredAnnotation) {
+        RemoteObjectGatewayHelper helper =
+                getRemoteObjectGatewayHelperForFrame(frameHost, requiredAnnotation);
+        helper.gateway.addNamedObject(name, helper.host.getRegistry().getObjectId(object));
+    }
+
+    private RemoteObjectGatewayHelper getRemoteObjectGatewayHelperForFrame(
+            RenderFrameHost frameHost, Class<? extends Annotation> requiredAnnotation) {
+        // Only create one instance of RemoteObjectHostImpl per frame and store it in a map so it is
+        // reused in future calls.
+        if (!mRemoteObjectGatewayHelpers.containsKey(frameHost)) {
+            RemoteObjectRegistry registry = new RemoteObjectRegistry(mRetainingSet);
+
+            // Construct a RemoteObjectHost implementation.
+            RemoteObjectHostImpl host = new RemoteObjectHostImpl(
+                    requiredAnnotation, new RemoteObjectAuditorImpl(), registry);
+
+            RemoteObjectGatewayFactory factory = frameHost.getRemoteInterfaces().getInterface(
+                    RemoteObjectGatewayFactory.MANAGER);
+
+            Pair<RemoteObjectGateway.Proxy, InterfaceRequest<RemoteObjectGateway>> result =
+                    RemoteObjectGateway.MANAGER.getInterfaceRequest(CoreImpl.getInstance());
+            factory.createRemoteObjectGateway(host, result.second);
+            mRemoteObjectGatewayHelpers.put(
+                    frameHost, new RemoteObjectGatewayHelper(result.first, host));
+        }
+
+        return mRemoteObjectGatewayHelpers.get(frameHost);
+    }
+}