cc: Setup API to release OutputSurface from LTHClient.

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index a1291cd7543354e49f373af0c63b369ab466d5a2..69ef40caf645e3e0b5408d7676a76095c3c6f60f 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -215,8 +215,8 @@ RenderWidgetCompositor::RenderWidgetCompositor(
       widget_(widget),
       compositor_deps_(compositor_deps),
       layout_and_paint_async_callback_(nullptr),
-      weak_factory_(this) {
-}
+      did_give_back_output_surface_(false),
+      weak_factory_(this) {}
 
 void RenderWidgetCompositor::Initialize() {
   base::CommandLine* cmd = base::CommandLine::ForCurrentProcess();
@@ -956,6 +956,13 @@ void RenderWidgetCompositor::DidFailToInitializeOutputSurface() {
                             weak_factory_.GetWeakPtr()));
 }
 
+scoped_ptr<cc::OutputSurface> RenderWidgetCompositor::GiveBackOutputSurface() {
+  did_give_back_output_surface_ = true;

[sohanjg, 2015/08/12 10:50:29]

i have added this member to reflect the compositor's state. But couldnt find any
uasge.

+  num_failed_recreate_attempts_ = 0;
+  layer_tree_host_->SetVisible(false);
+  return layer_tree_host_->GetOutputSurface().Pass();
+}
+
 void RenderWidgetCompositor::WillCommit() {
   InvokeLayoutAndPaintCallback();
 }