Hide pinch viewport scrollbars when near minimum scale.

cc/trees/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/trees/layer_tree_settings.h"
 
 #include <GLES2/gl2.h>
 #include <limits>
 
 #include "base/command_line.h"
@@ skipping 16 matching lines @@
       accelerated_animation_enabled(true),
       can_use_lcd_text(true),
       use_distance_field_text(false),
       gpu_rasterization_enabled(false),
       gpu_rasterization_forced(false),
       create_low_res_tiling(false),
       scrollbar_animator(NoAnimator),
       scrollbar_fade_delay_ms(0),
       scrollbar_fade_resize_delay_ms(0),
       scrollbar_fade_duration_ms(0),
+      scrollbar_show_scale_threshold(1.0f),
       solid_color_scrollbar_color(SK_ColorWHITE),
       calculate_top_controls_position(false),
       timeout_and_draw_when_animation_checkerboards(true),
       maximum_number_of_failed_draws_before_draw_is_forced_(3),
       layer_transforms_should_scale_layer_contents(false),
       layers_always_allowed_lcd_text(false),
       minimum_contents_scale(0.0625f),
       low_res_contents_scale_factor(0.25f),
       top_controls_show_threshold(0.5f),
       top_controls_hide_threshold(0.5f),
@@ skipping 20 matching lines @@
       scheduled_raster_task_limit(32),
       use_occlusion_for_tile_prioritization(false),
       record_full_layer(false),
       use_display_lists(false),
       verify_property_trees(false) {
 }
 
 LayerTreeSettings::~LayerTreeSettings() {}
 
 }  // namespace cc