[Android WebView] Implement Ubercomp for Render Thread support

content/browser/android/in_process/synchronous_compositor_impl.cc

Index: content/browser/android/in_process/synchronous_compositor_impl.cc
diff --git a/content/browser/android/in_process/synchronous_compositor_impl.cc b/content/browser/android/in_process/synchronous_compositor_impl.cc
index 347c3631ac617ba93f693049580faf8f0da83a45..35be7261cbb77677acc182272ab0192d96aa541f 100644
--- a/content/browser/android/in_process/synchronous_compositor_impl.cc
+++ b/content/browser/android/in_process/synchronous_compositor_impl.cc
@@ -66,7 +66,8 @@ SynchronousCompositorImpl::SynchronousCompositorImpl(WebContents* contents)
     : compositor_client_(NULL),
       output_surface_(NULL),
       contents_(contents),
-      input_handler_(NULL) {
+      input_handler_(NULL),
+      weak_ptr_factory_(this) {
   DCHECK(contents);
 }
 
@@ -110,24 +111,60 @@ void SynchronousCompositorImpl::ReleaseHwDraw() {
   g_factory.Get().CompositorReleasedHardwareDraw();
 }
 
-bool SynchronousCompositorImpl::DemandDrawHw(
-      gfx::Size surface_size,
-      const gfx::Transform& transform,
-      gfx::Rect viewport,
-      gfx::Rect clip,
-      bool stencil_enabled) {
+gpu::GLInProcessContext* SynchronousCompositorImpl::GetShareContext() {
+  DCHECK(CalledOnValidThread());
+  return g_factory.Get().GetShareContext();
+}
+
+bool SynchronousCompositorImpl::DemandDrawHw(gfx::Size surface_size,
+                                             const gfx::Transform& transform,
+                                             gfx::Rect viewport,
+                                             gfx::Rect clip,
+                                             bool stencil_enabled,
+                                             cc::CompositorFrame* frame) {
   DCHECK(CalledOnValidThread());

[no sievers, 2014/05/20 20:48:26]

So this is either on the UI thread (legacy) or on the RenderThread (ubercomp)?

I find it a bit confusing that this class deals with both child and parent
compositor stuff.

Also it seems like keeping the legacy path around makes the code noticeably more
confusing than it already is (or needs to be for other reasons).

[boliu, 2014/05/21 01:33:26]

Ehh, exact opposite.

This is called on UI thread in ubercomp (correct behavior), and RT thread on
legacy (which will fail this DCHECK, and we are relying on not compiling in
DCHECKs to make legacy path work)
There isn't any parent stuff...? do you mean parent as in updating frame
metadata? Or just the fact it could be called on RT on legacy path?
There are the PostTasks to UI. But nothing else too bad..?

   DCHECK(output_surface_);
+  DCHECK(frame);
 
-  return output_surface_->DemandDrawHw(
-      surface_size, transform, viewport, clip, stencil_enabled);
+  bool result = output_surface_->DemandDrawHw(
+      surface_size, transform, viewport, clip, stencil_enabled, frame);
+  if (result)
+    UpdateFrameMetaData(frame->metadata);
+  return result;
+}
+
+void SynchronousCompositorImpl::ReturnResources(
+    const cc::CompositorFrameAck& frame_ack) {
+  DCHECK(CalledOnValidThread());
+  output_surface_->ReturnResources(frame_ack);
 }
 
 bool SynchronousCompositorImpl::DemandDrawSw(SkCanvas* canvas) {
   DCHECK(CalledOnValidThread());
   DCHECK(output_surface_);
 
-  return output_surface_->DemandDrawSw(canvas);
+  cc::CompositorFrame frame;
+  bool result = output_surface_->DemandDrawSw(canvas, &frame);
+  if (result)
+    UpdateFrameMetaData(frame.metadata);
+  return result;
+}
+
+void SynchronousCompositorImpl::UpdateFrameMetaData(
+    const cc::CompositorFrameMetadata& frame_metadata) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&SynchronousCompositorImpl::UpdateFrameMetaData,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   frame_metadata));
+    return;
+  }
+  RenderWidgetHostViewAndroid* rwhv = static_cast<RenderWidgetHostViewAndroid*>(
+      contents_->GetRenderWidgetHostView());
+  if (rwhv)
+    rwhv->SynchronousFrameMetadata(frame_metadata);
 }
 
 void SynchronousCompositorImpl::SetMemoryPolicy(
@@ -207,14 +244,6 @@ InputEventAckState SynchronousCompositorImpl::HandleInputEvent(
       contents_->GetRoutingID(), input_event);
 }
 
-void SynchronousCompositorImpl::UpdateFrameMetaData(
-    const cc::CompositorFrameMetadata& frame_metadata) {
-  RenderWidgetHostViewAndroid* rwhv = static_cast<RenderWidgetHostViewAndroid*>(
-      contents_->GetRenderWidgetHostView());
-  if (rwhv)
-    rwhv->SynchronousFrameMetadata(frame_metadata);
-}
-
 void SynchronousCompositorImpl::DidActivatePendingTree() {
   if (compositor_client_)
     compositor_client_->DidUpdateContent();