gpu: Add the ability to wait on upload completion.

content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc

Index: content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index ba010d5001cb114b0c42c9954df4408676c40ace..e227a0018bb4e2190cae7070ef2ce085759fa4f6 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -1698,6 +1698,11 @@ void WebGraphicsContext3DCommandBufferImpl::asyncTexSubImage2DCHROMIUM(
       width, height, format, type, pixels);
 }
 
+void WebGraphicsContext3DCommandBufferImpl::waitAsyncTexImage2DCHROMIUM(
+    WGC3Denum target) {
+  return gl_->WaitAsyncTexImage2DCHROMIUM(target);
+}
+
 GrGLInterface* WebGraphicsContext3DCommandBufferImpl::onCreateGrGLInterface() {
   return webkit::gpu::CreateCommandBufferSkiaGLBinding();
 }