Initialize device scale factor correctly on Android

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 9e723b5cc14f45f8ac68f62d6c46b406f2156fd9..d5751d8f862f2cf7780da7c384c1bf89353a5c9b 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -35,6 +35,7 @@
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 #include "third_party/skia/include/core/SkShader.h"
 #include "ui/base/ui_base_switches.h"
+#include "ui/gfx/display.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/skia_util.h"
@@ -118,18 +119,15 @@ RenderWidget::RenderWidget(WebKit::WebPopupType popup_type,
   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);
+
+  scoped_ptr<gfx::Display> display(new gfx::Display());

[jamesr, 2012/11/06 18:36:14]

why heap allocate? can't this go on the stack?

+  display->SetScaleAndBounds(
+      std::min(screen_info.horizontalDPI, screen_info.verticalDPI) /
+      kStandardDPI, display->bounds());
+  device_scale_factor_ = display->device_scale_factor();
 }
 
 RenderWidget::~RenderWidget() {