Delegate root layer scroll offset to android_webview.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 521b3306ae5de6507c109096674df0c8ef2e8209..acffff9baee43513ed45d655e595cca3a191432b 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -57,8 +57,10 @@
 #include "webkit/plugins/npapi/webplugin.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/renderer/compositor_bindings/web_rendering_stats_impl.h"
+#include "webkit/renderer/compositor_bindings/web_to_ccinput_handler_adapter.h"
 
 #if defined(OS_ANDROID)
+#include "content/renderer/android/synchronous_compositor_impl.h"
 #include "content/renderer/android/synchronous_compositor_output_surface.h"
 #endif
 
@@ -582,12 +584,9 @@ bool RenderWidget::ForceCompositingModeEnabled() {
 scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface() {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
-#if defined(OS_ANDROID)
-  if (command_line.HasSwitch(switches::kEnableSynchronousRendererCompositor)) {
-    return scoped_ptr<cc::OutputSurface>(
-        new SynchronousCompositorOutputSurface(routing_id()));
+  if (GetSynchronousCompositor()) {
+    return GetSynchronousCompositor()->CreateOutputSurface();
   }
-#endif
 
   if (command_line.HasSwitch(switches::kEnableSoftwareCompositingGLAdapter)) {
       return scoped_ptr<cc::OutputSurface>(
@@ -626,6 +625,18 @@ scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface() {
           new CompositorOutputSurface(routing_id(), context, NULL));
 }
 
+SynchronousCompositorImpl* RenderWidget::GetSynchronousCompositor() {
+#if defined(OS_ANDROID)
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  if (command_line.HasSwitch(switches::kEnableSynchronousRendererCompositor)) {
+    synchronous_compositor_.reset(new SynchronousCompositorImpl(routing_id()));
+  }
+  return synchronous_compositor_.get();
+#else
+  return NULL;
+#endif
+}
+
 void RenderWidget::OnViewContextSwapBuffersAborted() {
   TRACE_EVENT0("renderer", "RenderWidget::OnSwapBuffersAborted");
   while (!updates_pending_swap_.empty()) {
@@ -1448,6 +1459,13 @@ void RenderWidget::didActivateCompositor(int input_handler_identifier) {
   }
 #endif
 
+#if defined(OS_ANDROID)
+  if (GetSynchronousCompositor()) {
+    GetSynchronousCompositor()->didCreateInputHandler(
+        compositor_->GetInputHandler());
+  }
+#endif
+
   is_accelerated_compositing_active_ = true;
   Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
       routing_id_, is_accelerated_compositing_active_));