cc: Generate tilings at other scales for impl-side painting

cc/layer_tree_settings.cc

 // Copyright 2011 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 "cc/layer_tree_settings.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 10 matching lines @@
     , perTilePaintingEnabled(false)
     , partialSwapEnabled(false)
     , acceleratedAnimationEnabled(true)
     , pageScalePinchZoomEnabled(false)
     , backgroundColorInsteadOfCheckerboard(false)
     , showOverdrawInTracing(false)
     , canUseLCDText(true)
     , shouldClearRootRenderPass(true)
     , useLinearFadeScrollbarAnimator(false)
     , minimumContentsScale(0.0625)
+    , lowResContentsScaleFactor(0.125f)
     , refreshRate(0)
     , maxPartialTextureUpdates(std::numeric_limits<size_t>::max())
     , numRasterThreads(1)
     , defaultTileSize(gfx::Size(256, 256))
     , maxUntiledLayerSize(gfx::Size(512, 512))
     , minimumOcclusionTrackingSize(gfx::Size(160, 160))
 {
     // TODO(danakj): Move this to chromium when we don't go through the WebKit API anymore.
     compositorFrameMessage = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kEnableCompositorFrameMessage);
     implSidePainting = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kEnableImplSidePainting);
@@ skipping 39 matching lines @@
                 num_raster_threads;
         }
     }
 }
 
 LayerTreeSettings::~LayerTreeSettings()
 {
 }
 
 }  // namespace cc