Increase priority of raster threads on Android.

base/threading/platform_thread_unittest.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 "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 159 matching lines @@
 namespace {
 
 const ThreadPriority kThreadPriorityTestValues[] = {
 // Disable non-normal priority toggling on POSIX as it appears to be broken
 // (http://crbug.com/468793). This is prefered to disabling the tests altogether
 // on POSIX as it at least provides coverage for running this code under
 // "normal" priority.
 #if !defined(OS_POSIX)
     ThreadPriority::DISPLAY,
     ThreadPriority::REALTIME_AUDIO,
+    ThreadPriority::UI_BACKGROUND,
     // Keep BACKGROUND second to last to test backgrounding from other
     // priorities.
     ThreadPriority::BACKGROUND,
 #endif  // !defined(OS_POSIX)
     // Keep NORMAL last to test unbackgrounding.
     ThreadPriority::NORMAL
 };
 
 }  // namespace
 
@@ skipping 76 matching lines @@
   }
 
   // Restore current thread priority for follow-up tests.
   PlatformThread::SetThreadPriority(current_handle, ThreadPriority::NORMAL);
 
   thread.MarkForTermination();
   PlatformThread::Join(handle);
 }
 
 }  // namespace base