Convert AwViewMsg_ClearCache to a mojom message.

There are a series of messages that are sent to the RenderThreadObserver
of the webview. This maps ClearCache onto one of those messages.
Other targeted messages will be converted in followup CLs.

BUG=993189

Change-Id: I93d84f08bfcc74211ac175463754bf6b9d3d7ce8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2515043
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824874}

android_webview/browser/BUILD.gn

@@ -182,6 +182,7 @@ source_set("browser") {
     "//android_webview/browser/metrics",
     "//android_webview/browser/variations",
     "//android_webview/common",
+    "//android_webview/common:mojom",
     "//android_webview/proto:aw_variations_seed_proto",
     "//base",
     "//components/autofill/android/provider",

android_webview/browser/aw_contents.cc

@@ -752,7 +752,11 @@ void AwContents::ClearCache(JNIEnv* env,
                             const JavaParamRef<jobject>& obj,
                             jboolean include_disk_files) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  render_view_host_ext_->ClearCache();
+  AwRenderProcess* aw_render_process =
+      AwRenderProcess::GetInstanceForRenderProcessHost(
+          web_contents_->GetMainFrame()->GetProcess());
+
+  aw_render_process->ClearCache();
 
   if (include_disk_files) {
     content::BrowsingDataRemover* remover =

android_webview/browser/aw_render_process.cc

@@ -56,11 +56,24 @@ AwRenderProcess::~AwRenderProcess() {
   java_obj_.Reset();
 }
 
+void AwRenderProcess::ClearCache() {
+  // If the renderer is in between the Init and the Ready phase (ie. hasn't
+  // started child process yet), clearing the cache will not do anything so it
+  // is fine to drop it here if there isn't a |renderer_remote_|.
+  if (renderer_remote_) {
+    renderer_remote_->ClearCache();
+  }
+}
+
 void AwRenderProcess::Ready() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   Java_AwRenderProcess_setNative(AttachCurrentThread(), java_obj_,
                                  reinterpret_cast<jlong>(this));
+
+  renderer_remote_.reset();
+  render_process_host_->GetChannel()->GetRemoteAssociatedInterface(
+      &renderer_remote_);
 }
 
 void AwRenderProcess::Cleanup() {

android_webview/browser/aw_render_process.h

@@ -5,11 +5,12 @@
 #ifndef ANDROID_WEBVIEW_BROWSER_AW_RENDER_PROCESS_H_
 #define ANDROID_WEBVIEW_BROWSER_AW_RENDER_PROCESS_H_
 
+#include "android_webview/common/mojom/renderer.mojom.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/weak_ptr.h"
 #include "base/supports_user_data.h"
-
 #include "content/public/browser/render_process_host_observer.h"
+#include "mojo/public/cpp/bindings/associated_remote.h"
 
 namespace android_webview {
 
@@ -31,6 +32,8 @@ class AwRenderProcess : public content::RenderProcessHostObserver,
   explicit AwRenderProcess(content::RenderProcessHost* render_process_host);
   ~AwRenderProcess() override;
 
+  void ClearCache();
+
  private:
   void Ready();
   void Cleanup();
@@ -46,6 +49,8 @@ class AwRenderProcess : public content::RenderProcessHostObserver,
 
   content::RenderProcessHost* render_process_host_;
 
+  mojo::AssociatedRemote<mojom::Renderer> renderer_remote_;
+
   base::WeakPtrFactory<AwRenderProcess> weak_factory_{this};
   DISALLOW_COPY_AND_ASSIGN(AwRenderProcess);
 };

android_webview/browser/renderer_host/aw_render_view_host_ext.cc

@@ -53,11 +53,6 @@ void AwRenderViewHostExt::DocumentHasImages(DocumentHasImagesResult result) {
   }
 }
 
-void AwRenderViewHostExt::ClearCache() {
-  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  web_contents()->GetRenderViewHost()->Send(new AwViewMsg_ClearCache);
-}
-
 void AwRenderViewHostExt::KillRenderProcess() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   web_contents()->GetRenderViewHost()->Send(new AwViewMsg_KillProcess);

android_webview/browser/renderer_host/aw_render_view_host_ext.h

@@ -44,9 +44,6 @@ class AwRenderViewHostExt : public content::WebContentsObserver {
   using DocumentHasImagesResult = base::OnceCallback<void(bool)>;
   void DocumentHasImages(DocumentHasImagesResult result);
 
-  // Clear all WebCore memory cache (not only for this view).
-  void ClearCache();
-
   // Tells render process to kill itself (only for testing).
   void KillRenderProcess();
 

android_webview/common/BUILD.gn

@@ -59,3 +59,12 @@ source_set("common") {
     "//url",
   ]
 }
+
+mojom("mojom") {
+  # We don't want Blink variants of bindings to be generated.
+  disable_variants = true
+
+  sources = [ "mojom/renderer.mojom" ]
+
+  public_deps = [ "//mojo/public/mojom/base" ]
+}

android_webview/common/mojom/OWNERS

+per-file *.mojom=set noparent
+per-file *.mojom=file://ipc/SECURITY_OWNERS

android_webview/common/mojom/renderer.mojom

+// 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.
+
+module android_webview.mojom;
+
+// Similar to content.mojom.Renderer. This interface adds additional
+// things that webview needs from the renderer process.
+interface Renderer {
+  // Clear the memory cache. The cache is process wide so this will influence
+  // other webview instances as well.
+  ClearCache();
+};

android_webview/common/render_view_messages.h

@@ -40,9 +40,6 @@ IPC_STRUCT_TRAITS_END()
 // RenderView messages
 // These are messages sent from the browser to the renderer process.
 
-// Tells the renderer to drop all WebCore memory cache.
-IPC_MESSAGE_CONTROL0(AwViewMsg_ClearCache)
-
 // Tells render process to kill itself (only for testing).
 IPC_MESSAGE_CONTROL0(AwViewMsg_KillProcess)
 

android_webview/renderer/BUILD.gn

@@ -32,6 +32,7 @@ source_set("renderer") {
     "//android_webview:generate_aw_resources",
     "//android_webview:generate_aw_strings",
     "//android_webview/common",
+    "//android_webview/common:mojom",
     "//base",
     "//components/android_system_error_page",
     "//components/autofill/content/renderer",

android_webview/renderer/aw_render_thread_observer.cc

@@ -6,6 +6,7 @@
 
 #include "android_webview/common/render_view_messages.h"
 #include "ipc/ipc_message_macros.h"
+#include "third_party/blink/public/common/associated_interfaces/associated_interface_registry.h"
 #include "third_party/blink/public/platform/web_cache.h"
 #include "third_party/blink/public/platform/web_network_state_notifier.h"
 
@@ -21,7 +22,6 @@ bool AwRenderThreadObserver::OnControlMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(AwRenderThreadObserver, message)
-    IPC_MESSAGE_HANDLER(AwViewMsg_ClearCache, OnClearCache)
     IPC_MESSAGE_HANDLER(AwViewMsg_KillProcess, OnKillProcess)
     IPC_MESSAGE_HANDLER(AwViewMsg_SetJsOnlineProperty, OnSetJsOnlineProperty)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -29,7 +29,27 @@ bool AwRenderThreadObserver::OnControlMessageReceived(
   return handled;
 }
 
-void AwRenderThreadObserver::OnClearCache() {
+void AwRenderThreadObserver::RegisterMojoInterfaces(
+    blink::AssociatedInterfaceRegistry* associated_interfaces) {
+  // base::Unretained can be used here because the associated_interfaces
+  // is owned by the RenderThread and will live for the duration of the
+  // RenderThread.
+  associated_interfaces->AddInterface(
+      base::BindRepeating(&AwRenderThreadObserver::OnRendererAssociatedRequest,
+                          base::Unretained(this)));
+}
+
+void AwRenderThreadObserver::UnregisterMojoInterfaces(
+    blink::AssociatedInterfaceRegistry* associated_interfaces) {
+  associated_interfaces->RemoveInterface(mojom::Renderer::Name_);
+}
+
+void AwRenderThreadObserver::OnRendererAssociatedRequest(
+    mojo::PendingAssociatedReceiver<mojom::Renderer> receiver) {
+  receiver_.Bind(std::move(receiver));
+}
+
+void AwRenderThreadObserver::ClearCache() {
   blink::WebCache::Clear();
 }
 

android_webview/renderer/aw_render_thread_observer.h

@@ -5,29 +5,40 @@
 #ifndef ANDROID_WEBVIEW_RENDERER_AW_RENDER_THREAD_OBSERVER_H_
 #define ANDROID_WEBVIEW_RENDERER_AW_RENDER_THREAD_OBSERVER_H_
 
-#include "content/public/renderer/render_thread_observer.h"
-
+#include "android_webview/common/mojom/renderer.mojom.h"
 #include "base/compiler_specific.h"
+#include "content/public/renderer/render_thread_observer.h"
+#include "mojo/public/cpp/bindings/associated_receiver.h"
 
 namespace android_webview {
 
 // A RenderThreadObserver implementation used for handling android_webview
 // specific render-process wide IPC messages.
-class AwRenderThreadObserver : public content::RenderThreadObserver {
+class AwRenderThreadObserver : public content::RenderThreadObserver,
+                               public mojom::Renderer {
  public:
   AwRenderThreadObserver();
   ~AwRenderThreadObserver() override;
 
   // content::RenderThreadObserver implementation.
   bool OnControlMessageReceived(const IPC::Message& message) override;
+  void RegisterMojoInterfaces(
+      blink::AssociatedInterfaceRegistry* associated_interfaces) override;
+  void UnregisterMojoInterfaces(
+      blink::AssociatedInterfaceRegistry* associated_interfaces) override;
 
  private:
-  void OnClearCache();
+  // mojom::Renderer overrides:
+  void ClearCache() override;
+
+  void OnRendererAssociatedRequest(
+      mojo::PendingAssociatedReceiver<mojom::Renderer> receiver);
   void OnKillProcess();
   void OnSetJsOnlineProperty(bool network_up);
+
+  mojo::AssociatedReceiver<mojom::Renderer> receiver_{this};
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_RENDERER_AW_RENDER_THREAD_OBSERVER_H_
-