Revert of Remove EnableThreadedCompositing from the browser.

content/browser/android/content_startup_flags.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/android/content_startup_flags.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 38 matching lines @@
     // internal code checks this directly, but it wouldn't normally get set when
     // we are implementing an embedded WebView.
     parsed_command_line->AppendSwitch(switches::kSingleProcess);
   } else {
     int default_maximum = RenderProcessHost::GetMaxRendererProcessCount();
     DCHECK(default_maximum <= static_cast<int>(kMaxRendererProcessCount));
     if (max_render_process_count < default_maximum)
       RenderProcessHost::SetMaxRendererProcessCount(max_render_process_count);
   }
 
+  parsed_command_line->AppendSwitch(switches::kEnableThreadedCompositing);
   parsed_command_line->AppendSwitch(
       switches::kEnableCompositingForFixedPosition);
   parsed_command_line->AppendSwitch(switches::kEnableAcceleratedOverflowScroll);
   parsed_command_line->AppendSwitch(switches::kEnableBeginFrameScheduling);
 
   parsed_command_line->AppendSwitch(switches::kEnableGestureTapHighlight);
   parsed_command_line->AppendSwitch(switches::kEnablePinch);
   parsed_command_line->AppendSwitch(switches::kEnableOverlayFullscreenVideo);
   parsed_command_line->AppendSwitch(switches::kEnableOverlayScrollbar);
   parsed_command_line->AppendSwitch(switches::kEnableOverscrollNotifications);
@@ skipping 22 matching lines @@
   }
 
   // Disable profiler timing by default.
   if (!parsed_command_line->HasSwitch(switches::kProfilerTiming)) {
     parsed_command_line->AppendSwitchASCII(
         switches::kProfilerTiming, switches::kProfilerTimingDisabledValue);
   }
 }
 
 }  // namespace content