Initialize device scale factor correctly on Android

content/renderer/render_widget.cc

 // Copyright (c) 2012 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/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 56 matching lines @@
 using WebKit::WebRect;
 using WebKit::WebScreenInfo;
 using WebKit::WebSize;
 using WebKit::WebTextDirection;
 using WebKit::WebTouchEvent;
 using WebKit::WebVector;
 using WebKit::WebWidget;
 
 namespace content {
 
-static const float kStandardDPI = 160;
-
 RenderWidget::RenderWidget(WebKit::WebPopupType popup_type,
                            const WebKit::WebScreenInfo& screen_info,
                            bool swapped_out)
     : routing_id_(MSG_ROUTING_NONE),
       surface_id_(0),
       webwidget_(NULL),
       opener_id_(MSG_ROUTING_NONE),
       init_complete_(false),
       current_paint_buf_(NULL),
       next_paint_flags_(0),
@@ skipping 13 matching lines @@
       input_method_is_active_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
       can_compose_inline_(true),
       popup_type_(popup_type),
       pending_window_rect_count_(0),
       suppress_next_char_events_(false),
       is_accelerated_compositing_active_(false),
       animation_update_pending_(false),
       invalidation_task_posted_(false),
       screen_info_(screen_info),
-      device_scale_factor_(1),
+      device_scale_factor_(screen_info_.deviceScaleFactor),
       throttle_input_events_(true),
       next_smooth_scroll_gesture_id_(0),
       is_threaded_compositing_enabled_(false) {
   if (!swapped_out)
     RenderProcess::current()->AddRefProcess();
   DCHECK(RenderThread::Get());
   has_disable_gpu_vsync_switch_ = CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kDisableGpuVsync);
-#if defined(OS_CHROMEOS) || defined(OS_MACOSX)
-  device_scale_factor_ = screen_info.verticalDPI / kStandardDPI;
-  // Unless an explicit scale factor was provided for testing, ensure the scale
-  // is integral.
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kForceDeviceScaleFactor))
-    device_scale_factor_ = static_cast<int>(device_scale_factor_);
-  device_scale_factor_ = std::max(1.0f, device_scale_factor_);
-#endif
   is_threaded_compositing_enabled_ =
       CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableThreadedCompositing);
 }
 
 RenderWidget::~RenderWidget() {
   DCHECK(!webwidget_) << "Leaking our WebWidget!";
   STLDeleteElements(&updates_pending_swap_);
   if (current_paint_buf_) {
     RenderProcess::current()->ReleaseTransportDIB(current_paint_buf_);
@@ skipping 1455 matching lines @@
 }
 
 void RenderWidget::OnSetTextDirection(WebTextDirection direction) {
   if (!webwidget_)
     return;
   webwidget_->setTextDirection(direction);
 }
 
 void RenderWidget::OnScreenInfoChanged(
     const WebKit::WebScreenInfo& screen_info) {
   screen_info_ = screen_info;

[oshima, 2012/11/14 16:52:35]

can you add 

// TODO(oshima): Update scale factor here and remove OnSetDeviceScaleFactor

?

 }
 
 void RenderWidget::OnUpdateScreenRects(const gfx::Rect& view_screen_rect,
                                        const gfx::Rect& window_screen_rect) {
   view_screen_rect_ = view_screen_rect;
   window_screen_rect_ = window_screen_rect;
   Send(new ViewHostMsg_UpdateScreenRects_ACK(routing_id()));
 }
 
 webkit::ppapi::PluginInstance* RenderWidget::GetBitmapForOptimizedPluginPaint(
@@ skipping 306 matching lines @@
 bool RenderWidget::WillHandleGestureEvent(
     const WebKit::WebGestureEvent& event) {
   return false;
 }
 
 bool RenderWidget::WebWidgetHandlesCompositorScheduling() const {
   return false;
 }
 
 }  // namespace content