Send vsync timebase updates to the browser compositor

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 14fa05a598e2dc7a85372c108265cfc6289bf56a..c89cdcc21f472700e3a86aea3e320f20ad5aa4b5 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -130,6 +130,7 @@ WebGraphicsContext3DCommandBufferImpl::WebGraphicsContext3DCommandBufferImpl(
       active_url_(active_url),
       swap_client_(swap_client),
       memory_allocation_changed_callback_(0),
+      update_vsync_time_callback_(0),
       context_lost_callback_(0),
       context_lost_reason_(GL_NO_ERROR),
       error_message_callback_(0),
@@ -704,6 +705,22 @@ void WebGraphicsContext3DCommandBufferImpl::
         base::Callback<void(const GpuMemoryAllocationForRenderer&)>());
 }
 
+void WebGraphicsContext3DCommandBufferImpl::
+    setUpdateVSyncTimeCallbackCHROMIUM(
+        WebGraphicsUpdateVSyncTimeCallbackCHROMIUM* callback) {
+  update_vsync_time_callback_ = callback;
+
+  if (!command_buffer_)
+    return;
+
+  if (callback)
+    command_buffer_->SetUpdateVSyncTimeCallback(base::Bind(
+        &WebGraphicsContext3DCommandBufferImpl::OnUpdateVSyncTime,
+        weak_ptr_factory_.GetWeakPtr()));
+  else
+    command_buffer_->SetUpdateVSyncTimeCallback(
+        base::Callback<void(int64)>());
+}
 
 void WebGraphicsContext3DCommandBufferImpl::copyTextureToParentTextureCHROMIUM(
     WebGLId texture, WebGLId parentTexture) {
@@ -1413,6 +1430,12 @@ void WebGraphicsContext3DCommandBufferImpl::OnMemoryAllocationChanged(
             allocation.suggest_have_backbuffer));
 }
 
+void WebGraphicsContext3DCommandBufferImpl::OnUpdateVSyncTime(int64 time) {
+  if (update_vsync_time_callback_)
+    update_vsync_time_callback_->onUpdateVSyncTime(time);
+}
+
+
 void WebGraphicsContext3DCommandBufferImpl::setErrorMessageCallback(
     WebGraphicsContext3D::WebGraphicsErrorMessageCallback* cb) {
   error_message_callback_ = cb;