Disable low res tilings on desktop.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 211 matching lines @@
 
   RenderThreadImpl* render_thread = RenderThreadImpl::current();
   // render_thread may be NULL in tests.
   if (render_thread) {
     settings.impl_side_painting =
         render_thread->is_impl_side_painting_enabled();
     settings.gpu_rasterization_forced =
         render_thread->is_gpu_rasterization_forced();
     settings.gpu_rasterization_enabled =
         render_thread->is_gpu_rasterization_enabled();
-    settings.create_low_res_tiling = render_thread->is_low_res_tiling_enabled();
     settings.can_use_lcd_text = render_thread->is_lcd_text_enabled();
     settings.use_distance_field_text =
         render_thread->is_distance_field_text_enabled();
     settings.use_zero_copy = render_thread->is_zero_copy_enabled();
     settings.use_one_copy = render_thread->is_one_copy_enabled();
   }
 
   if (cmd->HasSwitch(switches::kEnableBleedingEdgeRenderingFastPaths)) {
     settings.recording_mode = cc::LayerTreeSettings::RecordWithSkRecord;
   }
@@ skipping 142 matching lines @@
   } else {
     // On other devices we have increased memory excessively to avoid
     // raster-on-demand already, so now we reserve 50% _only_ to avoid
     // raster-on-demand, and use 50% of the memory otherwise.
     settings.max_memory_for_prepaint_percentage = 50;
   }
   // Webview does not own the surface so should not clear it.
   settings.should_clear_root_render_pass =
       !synchronous_compositor_factory;
 
+  // TODO(danakj): Only do this on low end devices.
+  settings.create_low_res_tiling = true;
+
 #elif !defined(OS_MACOSX)
   if (ui::IsOverlayScrollbarEnabled()) {
     settings.scrollbar_animator = cc::LayerTreeSettings::Thinning;
     settings.solid_color_scrollbar_color = SkColorSetARGB(128, 128, 128, 128);
   } else if (cmd->HasSwitch(cc::switches::kEnablePinchVirtualViewport)) {
     // use_pinch_zoom_scrollbars is only true on desktop when non-overlay
     // scrollbars are in use.
     settings.use_pinch_zoom_scrollbars = true;
     settings.scrollbar_animator = cc::LayerTreeSettings::LinearFade;
     settings.solid_color_scrollbar_color = SkColorSetARGB(128, 128, 128, 128);
   }
   settings.scrollbar_fade_delay_ms = 500;
   settings.scrollbar_fade_duration_ms = 300;
 #endif
 
+  if (cmd->HasSwitch(switches::kEnableLowResTiling))
+    settings.create_low_res_tiling = true;
+  if (cmd->HasSwitch(switches::kDisableLowResTiling))
+    settings.create_low_res_tiling = false;
+
   compositor->Initialize(settings);
 
   return compositor.Pass();
 }
 
 RenderWidgetCompositor::RenderWidgetCompositor(RenderWidget* widget,
                                                bool threaded)
     : threaded_(threaded),
       widget_(widget),
       send_v8_idle_notification_after_commit_(false) {
@@ skipping 413 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content