[Aura] Added Support for rendering software compositor frames as cc::TextureLayers.

ui/compositor/layer.h

Index: ui/compositor/layer.h
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index a5afd6b86c853ce6becb25b56f65fd90b5c09a66..1159d0b485e83d97e8bc814dd146dd2b713ef249 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -17,6 +17,7 @@
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/texture_layer_client.h"
+#include "cc/resources/texture_mailbox.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/compositor/compositor.h"
@@ -250,6 +251,11 @@ class COMPOSITOR_EXPORT Layer
   void SetExternalTexture(ui::Texture* texture);
   ui::Texture* external_texture() { return texture_.get(); }
 
+  // Set new TextureMailbox for this layer. Note that |mailbox| may hold a
+  // shared memory resource or an actual mailbox for a texture.
+  void SetTextureMailbox(const cc::TextureMailbox& mailbox, float scale_factor);
+  cc::TextureMailbox GetTextureMailbox(float* scale_factor);
+
   // Sets a delegated frame, coming from a child compositor.
   void SetDelegatedFrame(scoped_ptr<cc::DelegatedFrameData> frame,
                          gfx::Size frame_size_in_dip);
@@ -465,6 +471,12 @@ class COMPOSITOR_EXPORT Layer
   // A cached copy of |Compositor::device_scale_factor()|.
   float device_scale_factor_;
 
+  // A cached copy of the TextureMailbox given texture_layer_.
+  cc::TextureMailbox mailbox_;
+
+  // Device scale factor in which mailbox_ was rendered in.
+  float mailbox_scale_factor_;
+
   // The size of the delegated frame in DIP, set when SetDelegatedFrame was
   // called.
   gfx::Size delegated_frame_size_in_dip_;