Fix high-DPI on Windows to make use of DIP scaling in WebKit.

ui/base/win/dpi.cc

Index: ui/base/win/dpi.cc
diff --git a/ui/base/win/dpi.cc b/ui/base/win/dpi.cc
index c9982924bd5ad0139f07313bb0478ecbf930f8ae..2a2e61a1d65a79f9bb9ca54c99825b5ba75d28cf 100644
--- a/ui/base/win/dpi.cc
+++ b/ui/base/win/dpi.cc
@@ -7,12 +7,25 @@
 #include <windows.h>
 
 #include "base/win/scoped_hdc.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/point_conversions.h"
+#include "ui/gfx/rect_conversions.h"
+#include "ui/gfx/size_conversions.h"
 
 namespace {
 
 int kDefaultDPIX = 96;
 int kDefaultDPIY = 96;
 
+
+float GetDeviceScaleFactorImpl() {
+#if defined(ENABLE_HIDPI)
+  return gfx::Display::GetForcedDeviceScaleFactor();
+#else
+  return 1.0f;
+#endif
+}
+
 }  // namespace
 
 namespace ui {
@@ -52,4 +65,33 @@ void EnableHighDPISupport() {
     set_process_dpi_aware_func();
 }
 
+namespace win {
+
+gfx::Point ScreenToDIPPoint(const gfx::Point& pixel_point) {
+  return gfx::ToFlooredPoint(
+      gfx::ScalePoint(pixel_point, 1.0f / GetDeviceScaleFactorImpl()));
+}
+
+gfx::Rect ScreenToDIPRect(const gfx::Rect& pixel_bounds) {
+  return gfx::ToFlooredRectDeprecated(

[pkotwicz, 2013/01/23 19:39:23]

Nit: Add TODO to use gfx::ToNearestRect().

[kevers, 2013/01/23 21:37:00]

Based on description of method, ToNearestRect might not be the correct choice. 
Added TODO to choose a more appropriate method for float to int conversions.

+      gfx::ScaleRect(pixel_bounds, 1.0f / GetDeviceScaleFactorImpl()));
+}
+
+gfx::Rect DIPToScreenRect(const gfx::Rect& dip_bounds) {
+  return gfx::ToFlooredRectDeprecated(
+      gfx::ScaleRect(dip_bounds, GetDeviceScaleFactorImpl()));
+}
+
+gfx::Size ScreenToDIPSize(const gfx::Size& size_in_pixels) {
+  return gfx::ToFlooredSize(
+      gfx::ScaleSize(size_in_pixels, 1.0f / GetDeviceScaleFactorImpl()));
+}
+
+gfx::Size DIPToScreenSize(const gfx::Size& dip_size) {
+  return gfx::ToFlooredSize(
+      gfx::ScaleSize(dip_size, GetDeviceScaleFactorImpl()));
+}
+
+}  // namespace win
+
 }  // namespace ui