content: Use background priority for raster thread in browser compositor on Android.

content/browser/renderer_host/compositor_impl_android.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/browser/renderer_host/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
@@ skipping 127 matching lines @@
 
 
 int g_surface_id_namespace = 0;
 
 class SingleThreadTaskGraphRunner
     : public cc::TaskGraphRunner,
       public base::DelegateSimpleThread::Delegate {
  public:
   SingleThreadTaskGraphRunner() : worker_thread_(this, "CompositorWorker") {
     worker_thread_.Start();
+    worker_thread_.SetThreadPriority(base::kThreadPriority_Background);
   }
 
   ~SingleThreadTaskGraphRunner() override {
     Shutdown();
     worker_thread_.Join();
   }
 
  private:
   // Overridden from base::DelegateSimpleThread::Delegate:
   void Run() override { cc::TaskGraphRunner::Run(); }
@@ skipping 562 matching lines @@
 
 void CompositorImpl::SetNeedsAnimate() {
   needs_animate_ = true;
   if (!host_)
     return;
 
   host_->SetNeedsAnimate();
 }
 
 }  // namespace content