Update from chromium https://crrev.com/302282

cc/resources/resource_pool.cc

 // Copyright 2012 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/resources/resource_pool.h"
 
 #include "cc/resources/resource_provider.h"
 #include "cc/resources/scoped_resource.h"
 
 namespace cc {
@@ skipping 87 matching lines @@
 bool ResourcePool::ResourceUsageTooHigh() {
   if (resource_count_ > max_resource_count_)
     return true;
   if (memory_usage_bytes_ > max_memory_usage_bytes_)
     return true;
   if (unused_memory_usage_bytes_ > max_unused_memory_usage_bytes_)
     return true;
   return false;
 }
 
-void ResourcePool::CheckBusyResources() {
+void ResourcePool::CheckBusyResources(bool wait_if_needed) {
   ResourceList::iterator it = busy_resources_.begin();
 
   while (it != busy_resources_.end()) {
     ScopedResource* resource = *it;
 
+    if (wait_if_needed)
+      resource_provider_->WaitReadLockIfNeeded(resource->id());
+
     if (resource_provider_->CanLockForWrite(resource->id())) {
       DidFinishUsingResource(resource);
       it = busy_resources_.erase(it);
     } else {
       ++it;
     }
   }
 }
 
 void ResourcePool::DidFinishUsingResource(ScopedResource* resource) {
   unused_memory_usage_bytes_ += resource->bytes();
   unused_resources_.push_back(resource);
 }
 
 }  // namespace cc