Enable Canvas2D hardware acceleration for Android WebView

webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc

Index: webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc
===================================================================
--- webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc	(revision 243070)
+++ webkit/renderer/compositor_bindings/web_external_texture_layer_impl.cc	(working copy)
@@ -82,7 +82,7 @@
   }
   gpu::Mailbox name;
   name.SetName(client_mailbox.name);
-  if (bitmap)
+  if (bitmap && name.IsZero())

[boliu, 2014/01/06 18:16:13]

This is patching over another issue which I hacked around here:
https://codereview.chromium.org/124063003/diff/60001/cc/trees/layer_tree_host.cc

The right fix is that if we are in hardware canvas2d, then bitmap should be
false.

     *mailbox = cc::TextureMailbox(bitmap->shared_memory(), bitmap->size());
   else
     *mailbox = cc::TextureMailbox(name, client_mailbox.syncPoint);