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 e378ea85c2bde485deada82740b422fdbdef97a3..30af81cb8c6f168383a1c0299d6af8d56b725591 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -657,7 +657,8 @@ WebKit::WebGraphicsContext3D* Layer::Context3d() {
   return NULL;
 }
 
-bool Layer::PrepareTextureMailbox(cc::TextureMailbox* mailbox) {
+bool Layer::PrepareTextureMailbox(cc::TextureMailbox* mailbox,
+                                  bool use_shared_memory) {
   return false;
 }