[Android WebView] Implement Ubercomp for Render Thread support

android_webview/browser/deferred_gpu_command_service.cc

Index: android_webview/browser/deferred_gpu_command_service.cc
diff --git a/android_webview/browser/deferred_gpu_command_service.cc b/android_webview/browser/deferred_gpu_command_service.cc
index 601334ae7f923f6860811a76a163ad612ecc4585..ed1cf5731c5e4d0f7916f0c51119072a0cf4fa30 100644
--- a/android_webview/browser/deferred_gpu_command_service.cc
+++ b/android_webview/browser/deferred_gpu_command_service.cc
@@ -41,6 +41,12 @@ void DeferredGpuCommandService::SetInstance() {
   }
 }
 
+// static
+DeferredGpuCommandService* DeferredGpuCommandService::GetInstance() {
+  DCHECK(g_service.Get().get());
+  return g_service.Get().get();
+}
+
 DeferredGpuCommandService::DeferredGpuCommandService() {}
 
 DeferredGpuCommandService::~DeferredGpuCommandService() {
@@ -68,6 +74,7 @@ void DeferredGpuCommandService::ScheduleTask(const base::Closure& task) {
   if (ScopedAllowGL::IsAllowed()) {
     RunTasks();
   } else {
+    // TODO(boliu): Improve this to avoid PostTask storm.
     RequestProcessGLOnUIThread();
   }
 }