Remove "upgrading to 2x DSF for lower UI scale when 2x resoruces are available" option

ash/display/display_info.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 <stdio.h>
 #include <string>
 #include <vector>
 
 #include "ash/display/display_info.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/size_f.h"
 
 #if defined(OS_WIN)
 #include "ui/aura/window_tree_host.h"
 #include "ui/gfx/win/dpi.h"
 #endif
 
 namespace ash {
 namespace {
 
-// TODO(oshima): This feature is obsolete. Remove this after m38.
-bool allow_upgrade_to_high_dpi = false;
-
 bool use_125_dsf_for_ui_scaling = false;
 
 // Check the content of |spec| and fill |bounds| and |device_scale_factor|.
 // Returns true when |bounds| is found.
 bool GetDisplayBounds(
     const std::string& spec, gfx::Rect* bounds, float* device_scale_factor) {
   int width = 0;
   int height = 0;
   int x = 0;
   int y = 0;
   if (sscanf(spec.c_str(), "%dx%d*%f",
              &width, &height, device_scale_factor) >= 2 ||
       sscanf(spec.c_str(), "%d+%d-%dx%d*%f", &x, &y, &width, &height,
              device_scale_factor) >= 4) {
     bounds->SetRect(x, y, width, height);
     return true;
   }
   return false;
 }
 
-}
+}  // namespace
 
 DisplayMode::DisplayMode()
     : refresh_rate(0.0f),
       interlaced(false),
       native(false),
       ui_scale(1.0f),
       device_scale_factor(1.0f) {}
 
 DisplayMode::DisplayMode(const gfx::Size& size,
                          float refresh_rate,
@@ skipping 19 matching lines @@
       std::abs(ui_scale - other.ui_scale) < kEpsilon &&
       std::abs(device_scale_factor - other.device_scale_factor) < kEpsilon;
 }
 
 // satic
 DisplayInfo DisplayInfo::CreateFromSpec(const std::string& spec) {
   return CreateFromSpecWithID(spec, gfx::Display::kInvalidDisplayID);
 }
 
 // static
-void DisplayInfo::SetAllowUpgradeToHighDPI(bool enable) {
-  allow_upgrade_to_high_dpi = enable;
-}
 
 // static
 void DisplayInfo::SetUse125DSFForUIScaling(bool enable) {
   use_125_dsf_for_ui_scaling = enable;
 }
 
 // static
 DisplayInfo DisplayInfo::CreateFromSpecWithID(const std::string& spec,
                                               int64 id) {
   // Default bounds for a display.
@@ skipping 183 matching lines @@
 
 void DisplayInfo::SetBounds(const gfx::Rect& new_bounds_in_native) {
   bounds_in_native_ = new_bounds_in_native;
   size_in_pixel_ = new_bounds_in_native.size();
   UpdateDisplaySize();
 }
 
 float DisplayInfo::GetEffectiveDeviceScaleFactor() const {
   if (use_125_dsf_for_ui_scaling && device_scale_factor_ == 1.25f)
     return (configured_ui_scale_ == 0.8f) ? 1.25f : 1.0f;
-
-  if (allow_upgrade_to_high_dpi && configured_ui_scale_ < 1.0f &&
-      device_scale_factor_ == 1.0f) {
-    return 2.0f;
-  } else if (device_scale_factor_ == configured_ui_scale_) {
+  if (device_scale_factor_ == configured_ui_scale_)
     return 1.0f;
-  }
   return device_scale_factor_;
 }
 
 float DisplayInfo::GetEffectiveUIScale() const {
   if (use_125_dsf_for_ui_scaling && device_scale_factor_ == 1.25f)
     return (configured_ui_scale_ == 0.8f) ? 1.0f : configured_ui_scale_;
-
-  if (allow_upgrade_to_high_dpi && configured_ui_scale_ < 1.0f &&
-      device_scale_factor_ == 1.0f) {
-    return configured_ui_scale_ * 2.0f;
-  } else if (device_scale_factor_ == configured_ui_scale_) {
+  if (device_scale_factor_ == configured_ui_scale_)
     return 1.0f;
-  }
   return configured_ui_scale_;
 }
 
 void DisplayInfo::UpdateDisplaySize() {
   size_in_pixel_ = bounds_in_native_.size();
   if (!overscan_insets_in_dip_.empty()) {
     gfx::Insets insets_in_pixel =
         overscan_insets_in_dip_.Scale(device_scale_factor_);
     size_in_pixel_.Enlarge(-insets_in_pixel.width(), -insets_in_pixel.height());
   } else {
@@ skipping 69 matching lines @@
 }
 
 bool DisplayInfo::IsColorProfileAvailable(
     ui::ColorCalibrationProfile profile) const {
   return std::find(available_color_profiles_.begin(),
                    available_color_profiles_.end(),
                    profile) != available_color_profiles_.end();
 }
 
 }  // namespace ash