Drop frontbuffers with ui-use-gpu-process, synchronized with browser, decoupled from backbuffer dro…

content/browser/renderer_host/render_widget_host_view_aura.h

Index: content/browser/renderer_host/render_widget_host_view_aura.h
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 2253801f03038907e63fe6c71ba7823a50aa5cfd..ae56ae16ac39a57a5f97dc56d3df5b220b82a1f6 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -12,6 +12,7 @@
 #include "base/callback.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/browser/renderer_host/image_transport_factory.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/common/content_export.h"
@@ -52,7 +53,8 @@ class RenderWidgetHostViewAura
       public ui::TextInputClient,
       public aura::WindowDelegate,
       public aura::client::ActivationDelegate,
-      public ImageTransportFactoryObserver {
+      public ImageTransportFactoryObserver,
+      public base::SupportsWeakPtr<RenderWidgetHostViewAura> {
  public:
   virtual ~RenderWidgetHostViewAura();
 
@@ -115,7 +117,8 @@ class RenderWidgetHostViewAura
       int32 width_in_pixel,
       int32 height_in_pixel,
       uint64* surface_id,
-      TransportDIB::Handle* surface_handle) OVERRIDE;
+      TransportDIB::Handle* surface_handle,
+      int32 route_id) OVERRIDE;
   virtual void AcceleratedSurfaceRelease(uint64 surface_id) OVERRIDE;
   virtual void GetScreenInfo(WebKit::WebScreenInfo* results) OVERRIDE;
   virtual gfx::Rect GetRootWindowBounds() OVERRIDE;
@@ -225,6 +228,12 @@ class RenderWidgetHostViewAura
   // Called when window_ is removed from the window tree.
   void RemovingFromRootWindow();
 
+  void SetSurfaceNotInUseByCompositor();
+  void AdjustSurfaceProtection();
+
+  void CopyFromCompositingSurfaceFinished(base::Callback<void(bool)> callback,
+                                          bool result);
+
   ui::Compositor* GetCompositor();
 
   // The model object.
@@ -280,6 +289,20 @@ class RenderWidgetHostViewAura
 
   uint64 current_surface_;
 
+  // Protected means that the current_surface_ may be in use by ui and cannot
+  // be safely discarded. Things to consider are thumbnailer, compositor draw
+  // pending, and tab visibility.
+  bool current_surface_is_protected_;
+  bool current_surface_in_use_by_compositor_;
+
+  int pending_thumbnail_tasks_;
+
+  // This id increments every time surface_is_protected changes.
+  // Keeps gpu/browser IPC messages relying on protection state in sync.
+  uint32 protection_state_id_;
+
+  int32 surface_route_id_;
+
   gfx::GLSurfaceHandle shared_surface_handle_;
 
   // If non-NULL we're in OnPaint() and this is the supplied canvas.