android webview: allow cc to fail hardware draw

cc/trees/single_thread_proxy.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/single_thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
@@ skipping 336 matching lines @@
     DebugScopedSetImplThread impl(this);
 
     BlockingTaskRunner::CapturePostTasks blocked(
         blocking_main_thread_task_runner());
     scheduler_on_impl_thread_ = nullptr;
     layer_tree_host_impl_ = nullptr;
   }
   layer_tree_host_ = NULL;
 }
 
+void SingleThreadProxy::OnResourcelessSoftareDrawStateChanged(
+    bool resourceless_draw) {
+  NOTREACHED();
+}
+
 void SingleThreadProxy::OnCanDrawStateChanged(bool can_draw) {
   TRACE_EVENT1(
       "cc", "SingleThreadProxy::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(Proxy::IsImplThread());
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetCanDraw(can_draw);
 }
 
 void SingleThreadProxy::NotifyReadyToActivate() {
   TRACE_EVENT0("cc", "SingleThreadProxy::NotifyReadyToActivate");
@@ skipping 526 matching lines @@
       << "DidFinishImplFrame called while not inside an impl frame!";
   inside_impl_frame_ = false;
 #endif
 }
 
 void SingleThreadProxy::SendBeginFramesToChildren(const BeginFrameArgs& args) {
   layer_tree_host_->SendBeginFramesToChildren(args);
 }
 
 }  // namespace cc