Increase priority of raster threads on Android.

content/renderer/render_thread_impl.cc

 // Copyright (c) 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 "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <vector>
@@ skipping 651 matching lines @@
   // Note: Currently, gathering of pixel refs when using a single
   // raster thread doesn't provide any benefit. This might change
   // in the future but we avoid it for now to reduce the cost of
   // Picture::Create.
   is_gather_pixel_refs_enabled_ = num_raster_threads > 1;
 
   base::SimpleThread::Options thread_options;
 #if defined(OS_ANDROID) || defined(OS_LINUX)
   if (!command_line.HasSwitch(
           switches::kUseNormalPriorityForTileTaskWorkerThreads)) {
-    thread_options.set_priority(base::ThreadPriority::BACKGROUND);
+    thread_options.set_priority(base::ThreadPriority::UI_BACKGROUND);
   }
 #endif
   while (compositor_raster_threads_.size() <
          static_cast<size_t>(num_raster_threads)) {
     scoped_ptr<CompositorRasterThread> raster_thread(new CompositorRasterThread(
         compositor_task_graph_runner_.get(),
         base::StringPrintf("CompositorTileWorker%u",
                            static_cast<unsigned>(
                                compositor_raster_threads_.size() + 1)).c_str(),
         thread_options));
@@ skipping 1191 matching lines @@
 }
 
 void RenderThreadImpl::PendingRenderFrameConnect::OnConnectionError() {
   size_t erased =
       RenderThreadImpl::current()->pending_render_frame_connects_.erase(
           routing_id_);
   DCHECK_EQ(1u, erased);
 }
 
 }  // namespace content