Turn ThreadPriority enum into an enum class.

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 653 matching lines @@
           new CompositorRasterThread(
               compositor_task_graph_runner_.get(),
               base::StringPrintf(
                   "CompositorTileWorker%u",
                   static_cast<unsigned>(compositor_raster_threads_.size() + 1))
                   .c_str()));
       raster_thread->Start();
 #if defined(OS_ANDROID) || defined(OS_LINUX)
       if (!command_line.HasSwitch(
               switches::kUseNormalPriorityForTileTaskWorkerThreads)) {
-        raster_thread->SetThreadPriority(base::kThreadPriority_Background);
+        raster_thread->SetThreadPriority(base::ThreadPriority::BACKGROUND);
       }
 #endif
       compositor_raster_threads_.push_back(raster_thread.Pass());
     }
   }
 
   // In single process, browser main loop set up the discardable memory
   // allocator.
   if (!command_line.HasSwitch(switches::kSingleProcess)) {
     base::DiscardableMemoryAllocator::SetInstance(
@@ skipping 344 matching lines @@
 #if defined(OS_ANDROID)
     if (SynchronousCompositorFactory* factory =
         SynchronousCompositorFactory::GetInstance())
       compositor_message_loop_proxy_ =
           factory->GetCompositorMessageLoop();
 #endif
     if (!compositor_message_loop_proxy_.get()) {
       compositor_thread_.reset(new base::Thread("Compositor"));
       compositor_thread_->Start();
 #if defined(OS_ANDROID)
-      compositor_thread_->SetPriority(base::kThreadPriority_Display);
+      compositor_thread_->SetPriority(base::ThreadPriority::DISPLAY);
 #endif
       compositor_message_loop_proxy_ =
           compositor_thread_->message_loop_proxy();
       compositor_message_loop_proxy_->PostTask(
           FROM_HERE,
           base::Bind(base::IgnoreResult(&ThreadRestrictions::SetIOAllowed),
                      false));
     }
 
     InputHandlerManagerClient* input_handler_manager_client = NULL;
@@ skipping 800 matching lines @@
 }
 
 void RenderThreadImpl::PendingRenderFrameConnect::OnConnectionError() {
   size_t erased =
       RenderThreadImpl::current()->pending_render_frame_connects_.erase(
           routing_id_);
   DCHECK_EQ(1u, erased);
 }
 
 }  // namespace content