android webview: Keep zoom methods synchronous

content/renderer/android/synchronous_compositor_proxy.cc

Index: content/renderer/android/synchronous_compositor_proxy.cc
diff --git a/content/renderer/android/synchronous_compositor_proxy.cc b/content/renderer/android/synchronous_compositor_proxy.cc
index 4ecfdff1028a4e37565653883432c04887277cf1..0cdb1b0cb84aed7a54062d0a36c6119195dd51c1 100644
--- a/content/renderer/android/synchronous_compositor_proxy.cc
+++ b/content/renderer/android/synchronous_compositor_proxy.cc
@@ -171,6 +171,8 @@ void SynchronousCompositorProxy::OnMessageReceived(
     IPC_MESSAGE_HANDLER_DELAY_REPLY(SyncCompositorMsg_DemandDrawSw,
                                     DemandDrawSw)
     IPC_MESSAGE_HANDLER(SyncCompositorMsg_UpdateState, ProcessCommonParams)
+    IPC_MESSAGE_HANDLER(SyncCompositorMsg_SynchronousUpdateState,
+                        SynchronousUpdateState)
   IPC_END_MESSAGE_MAP()
 }
 
@@ -396,6 +398,15 @@ void SynchronousCompositorProxy::OnComputeScroll(
   }
 }
 
+void SynchronousCompositorProxy::SynchronousUpdateState(
+    const SyncCompositorCommonBrowserParams& common_params,
+    SyncCompositorCommonRendererParams* common_renderer_params) {
+  DCHECK(!inside_receive_);
+  base::AutoReset<bool> scoped_inside_receive(&inside_receive_, true);
+  ProcessCommonParams(common_params);
+  PopulateCommonParams(common_renderer_params);
+}
+
 void SynchronousCompositorProxy::DidOverscroll(
     const DidOverscrollParams& did_overscroll_params) {
   SyncCompositorCommonRendererParams params;