Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 44d060a63ead8d96cda20647e83152460a04d979..a9d05e47d21e1ce75d2731d560dedd0663dfaf0b 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -407,14 +407,14 @@ bool RenderWidgetHostViewAndroid::IsShowing() {
   return is_showing_ && content_view_core_;
 }
 
-void RenderWidgetHostViewAndroid::LockResources() {
+void RenderWidgetHostViewAndroid::LockSurfaceForCopy() {
   DCHECK(HasValidFrame());
   DCHECK(host_);
   DCHECK(!host_->is_hidden());
   frame_evictor_->LockFrame();
 }
 
-void RenderWidgetHostViewAndroid::UnlockResources() {
+void RenderWidgetHostViewAndroid::UnlockSurfaceForCopy() {
   DCHECK(HasValidFrame());
   frame_evictor_->UnlockFrame();
 }
@@ -849,6 +849,18 @@ void RenderWidgetHostViewAndroid::OnSwapCompositorFrame(
 
     DCHECK(frame->delegated_frame_data);
     DCHECK(!frame->delegated_frame_data->render_pass_list.empty());
+    if (frame_evictor_->FrameLocked()) {
+      base::Closure ack_callback =
+          base::Bind(&RenderWidgetHostViewAndroid::SendDelegatedFrameAck,
+                     weak_ptr_factory_.GetWeakPtr(),
+                     output_surface_id);
+
+      if (host_->is_hidden())
+        ack_callback.Run();
+      else
+        ack_callbacks_.push(ack_callback);
+      return;
+    }
 
     cc::RenderPass* root_pass =
         frame->delegated_frame_data->render_pass_list.back();
@@ -1381,6 +1393,9 @@ void RenderWidgetHostViewAndroid::OnDetachCompositor() {
 }
 
 void RenderWidgetHostViewAndroid::OnLostResources() {
+  while (frame_evictor_->FrameLocked()) {
+    UnlockSurfaceForCopy();
+  }
   if (texture_layer_.get())
     texture_layer_->SetIsDrawable(false);
   if (delegated_renderer_layer_.get())