Allow WebExternalTextureLayers to receive a bitmap along with a mailbox

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index d0b328d36fd3a91dbb0351d8c8facbbce12c2023..76bbc20bc36c495bf96c0f70696720122fb30550 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -662,7 +662,8 @@ WebKit::WebGraphicsContext3D* Layer::Context3d() {
   return NULL;
 }
 
-bool Layer::PrepareTextureMailbox(cc::TextureMailbox* mailbox) {
+bool Layer::PrepareTextureMailbox(cc::TextureMailbox* mailbox,
+                                  bool use_shared_memory) {
   return false;
 }