cc: Remove all traces of synchronous GPU rasterization

cc/trees/layer_tree_settings.h

 // 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.
 
 #ifndef CC_TREES_LAYER_TREE_SETTINGS_H_
 #define CC_TREES_LAYER_TREE_SETTINGS_H_
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/debug/layer_tree_debug_state.h"
@@ skipping 19 matching lines @@
   bool using_synchronous_renderer_compositor;
   bool report_overscroll_only_for_scrollable_axes;
   bool per_tile_painting_enabled;
   bool accelerated_animation_enabled;
   bool can_use_lcd_text;
   bool use_distance_field_text;
   bool gpu_rasterization_enabled;
   bool gpu_rasterization_forced;
   int gpu_rasterization_msaa_sample_count;
   float gpu_rasterization_skewport_target_time_in_seconds;
-  bool threaded_gpu_rasterization_enabled;
   bool create_low_res_tiling;
 
   enum ScrollbarAnimator {
     NO_ANIMATOR,
     LINEAR_FADE,
     THINNING,
   };
   ScrollbarAnimator scrollbar_animator;
   int scrollbar_fade_delay_ms;
   int scrollbar_fade_resize_delay_ms;
@@ skipping 36 matching lines @@
   bool use_compositor_animation_timelines;
 
   LayerTreeDebugState initial_debug_state;
 
   SchedulerSettings ToSchedulerSettings() const;
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_SETTINGS_H_