cc: Do not reset pending tree state incorrectly on aborted commits.

cc/trees/proxy_impl.cc

 // Copyright 2015 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/proxy_impl.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 166 matching lines @@
   SetNeedsCommitOnImplThread();
 }
 
 void ProxyImpl::BeginMainFrameAbortedOnImpl(
     CommitEarlyOutReason reason,
     base::TimeTicks main_thread_start_time) {
   TRACE_EVENT1("cc", "ProxyImpl::BeginMainFrameAbortedOnImplThread", "reason",
                CommitEarlyOutReasonToString(reason));
   DCHECK(IsImplThread());
   DCHECK(scheduler_->CommitPending());
-  DCHECK(!layer_tree_host_impl_->pending_tree());
 
   if (CommitEarlyOutHandledCommit(reason)) {
     SetInputThrottledUntilCommitOnImpl(false);
   }
   layer_tree_host_impl_->BeginMainFrameAborted(reason);
   scheduler_->NotifyBeginMainFrameStarted(main_thread_start_time);
   scheduler_->BeginMainFrameAborted(reason);
 }
 
 void ProxyImpl::FinishAllRenderingOnImpl(CompletionEvent* completion) {
@@ skipping 464 matching lines @@
 bool ProxyImpl::IsMainThreadBlocked() const {
   return task_runner_provider_->IsMainThreadBlocked();
 }
 
 ProxyImpl::BlockedMainCommitOnly& ProxyImpl::blocked_main_commit() {
   DCHECK(IsMainThreadBlocked() && commit_completion_event_);
   return main_thread_blocked_commit_vars_unsafe_;
 }
 
 }  // namespace cc