Allow renderer compositor message loop to be set by content embedder

Accomplished by adding a override method to ContentRendererClient
to return a MessageLoop, which if not null, is used as the renderer
compositor thread. In the process, make the ownership of the
compositor thread into RenderThreadImpl and rename CompositorThread
to InputHandlerManager.

Added a thread merge command line switch to control this in
android_webview.

BUG=179436


Review URL: https://chromiumcodereview.appspot.com/12383056

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@186682 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 2 deletions

diff --git a/android_webview/renderer/aw_content_renderer_client.cc b/android_webview/renderer/aw_content_renderer_client.cc
index a1995a3..b0abcd0 100644
--- a/android_webview/renderer/aw_content_renderer_client.cc
+++ b/android_webview/renderer/aw_content_renderer_client.cc
@@ -8,6 +8,7 @@
 #include "android_webview/common/url_constants.h"
 #include "android_webview/renderer/aw_render_view_ext.h"
 #include "android_webview/renderer/view_renderer.h"
+#include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "components/visitedlink/renderer/visitedlink_slave.h"
 #include "content/public/renderer/render_thread.h"
@@ -20,7 +21,9 @@
 
 namespace android_webview {
 
-AwContentRendererClient::AwContentRendererClient() {
+AwContentRendererClient::AwContentRendererClient(
+    MessageLoop* compositor_message_loop)
+    : compositor_message_loop_(compositor_message_loop) {
 }
 
 AwContentRendererClient::~AwContentRendererClient() {
@@ -93,4 +96,8 @@ void AwContentRendererClient::PrefetchHostName(const char* hostname,
   // Perhaps componentize chrome implementation or move to content/?
 }
 
+MessageLoop* AwContentRendererClient::OverrideCompositorMessageLoop() const {
+  return compositor_message_loop_;
+}
+
 }  // namespace android_webview
diff --git a/android_webview/renderer/aw_content_renderer_client.h b/android_webview/renderer/aw_content_renderer_client.h
index d938cd3..72112c2 100644
--- a/android_webview/renderer/aw_content_renderer_client.h
+++ b/android_webview/renderer/aw_content_renderer_client.h
@@ -18,7 +18,7 @@ namespace android_webview {
 
 class AwContentRendererClient : public content::ContentRendererClient {
  public:
-  AwContentRendererClient();
+  explicit AwContentRendererClient(MessageLoop* compositor_message_loop);
   virtual ~AwContentRendererClient();
 
   // ContentRendererClient implementation.
@@ -36,10 +36,12 @@ class AwContentRendererClient : public content::ContentRendererClient {
                                              size_t length) OVERRIDE;
   virtual bool IsLinkVisited(unsigned long long link_hash) OVERRIDE;
   virtual void PrefetchHostName(const char* hostname, size_t length) OVERRIDE;
+  virtual MessageLoop* OverrideCompositorMessageLoop() const OVERRIDE;
 
  private:
   scoped_ptr<AwRenderProcessObserver> aw_render_process_observer_;
   scoped_ptr<components::VisitedLinkSlave> visited_link_slave_;
+  MessageLoop* compositor_message_loop_;
 };
 
 }  // namespace android_webview