sync compositor: Add output_surface_id

android_webview/browser/hardware_renderer.h

Index: android_webview/browser/hardware_renderer.h
diff --git a/android_webview/browser/hardware_renderer.h b/android_webview/browser/hardware_renderer.h
index fe842f492c53eef8b38559aed62502d729e7a086..1b5127ac594a80ea3ce9d1b44f2011adb1d0fdfe 100644
--- a/android_webview/browser/hardware_renderer.h
+++ b/android_webview/browser/hardware_renderer.h
@@ -52,7 +52,8 @@ class HardwareRenderer : public cc::DisplayClient,
 
   void ReturnResourcesInChildFrame();
   void ReturnResourcesToCompositor(const cc::ReturnedResourceArray& resources,

[hush (inactive), 2016/03/21 20:43:55]

while you are at it, can you turn this function to private? It is only used
internally by this class.

[boliu, 2016/03/21 21:35:49]

Already private?

-                                   uint32_t compositor_routing_id);
+                                   uint32_t compositor_routing_id,
+                                   uint32_t output_surface_id);
 
   SharedRendererState* shared_renderer_state_;
 
@@ -79,6 +80,10 @@ class HardwareRenderer : public cc::DisplayClient,
   cc::SurfaceId child_id_;
   cc::SurfaceId root_id_;
   uint32_t compositor_id_;
+  // HardwareRenderer guarantees resources are returned in the order of
+  // output_surface_id, and resources for old output surfaces are dropped.
+  uint32_t last_committed_output_surface_id_;
+  uint32_t last_submitted_output_surface_id_;
 
   // This is owned by |display_|.
   ParentOutputSurface* output_surface_;