Multiple DPI Tracking for ScreenWin

ui/gfx/win/dpi.cc

Index: ui/gfx/win/dpi.cc
diff --git a/ui/gfx/win/dpi.cc b/ui/gfx/win/dpi.cc
index a958de4d1f3c2d6a1edb1807cab6ee9441902218..10de983df1efa2e75eb50e845f3c6a246711c0fe 100644
--- a/ui/gfx/win/dpi.cc
+++ b/ui/gfx/win/dpi.cc
@@ -17,22 +17,7 @@ const float kDefaultDPI = 96.f;
 
 float g_device_scale_factor = 0.f;
 
-float GetUnforcedDeviceScaleFactor() {
-  return g_device_scale_factor ?
-      g_device_scale_factor :
-      static_cast<float>(gfx::GetDPI().width()) / kDefaultDPI;
-}
-
-}  // namespace
-
-namespace gfx {
-
-void SetDefaultDeviceScaleFactor(float scale) {
-  DCHECK_NE(0.f, scale);
-  g_device_scale_factor = scale;
-}
-
-Size GetDPI() {
+gfx::Size GetDPI() {
   static int dpi_x = 0;
   static int dpi_y = 0;
   static bool should_initialize = true;
@@ -46,51 +31,36 @@ Size GetDPI() {
     dpi_x = GetDeviceCaps(screen_dc, LOGPIXELSX);
     dpi_y = GetDeviceCaps(screen_dc, LOGPIXELSY);
   }
-  return Size(dpi_x, dpi_y);
+  return gfx::Size(dpi_x, dpi_y);
 }
 
-float GetDPIScale() {
-  if (gfx::Display::HasForceDeviceScaleFactor())
-    return gfx::Display::GetForcedDeviceScaleFactor();
-  float dpi_scale = GetUnforcedDeviceScaleFactor();
-  return (dpi_scale <= 1.25f) ? 1.f : dpi_scale;
+float GetUnforcedDeviceScaleFactor() {
+  return g_device_scale_factor ?
+      g_device_scale_factor :
+      static_cast<float>(GetDPI().width()) / kDefaultDPI;
 }
 
-namespace win {
-
-Point ScreenToDIPPoint(const Point& pixel_point) {
-  return ScaleToFlooredPoint(pixel_point, 1.0f / GetDPIScale());
-}
+}  // namespace
 
-Point DIPToScreenPoint(const Point& dip_point) {
-  return ScaleToFlooredPoint(dip_point, GetDPIScale());
-}
+namespace gfx {
 
-Rect ScreenToDIPRect(const Rect& pixel_bounds) {
-  // It's important we scale the origin and size separately. If we instead
-  // calculated the size from the floored origin and ceiled right the size could
-  // vary depending upon where the two points land. That would cause problems
-  // for the places this code is used (in particular mapping from native window
-  // bounds to DIPs).
-  return Rect(ScreenToDIPPoint(pixel_bounds.origin()),
-              ScreenToDIPSize(pixel_bounds.size()));
+void SetDefaultDeviceScaleFactor(float scale) {
+  DCHECK_NE(0.f, scale);
+  g_device_scale_factor = scale;
 }
 
-Rect DIPToScreenRect(const Rect& dip_bounds) {
-  // See comment in ScreenToDIPRect for why we calculate size like this.
-  return Rect(DIPToScreenPoint(dip_bounds.origin()),
-              DIPToScreenSize(dip_bounds.size()));
+float GetDPIScale() {
+  if (gfx::Display::HasForceDeviceScaleFactor())
+    return gfx::Display::GetForcedDeviceScaleFactor();
+  float dpi_scale = GetUnforcedDeviceScaleFactor();
+  return (dpi_scale <= 1.25f) ? 1.f : dpi_scale;
 }
 
-Size ScreenToDIPSize(const Size& size_in_pixels) {
-  // Always ceil sizes. Otherwise we may be leaving off part of the bounds.
-  return ScaleToCeiledSize(size_in_pixels, 1.0f / GetDPIScale());
+int GetDPIFromScalingFactor(float device_scaling_factor) {
+  return kDefaultDPI * device_scaling_factor;
 }
 
-Size DIPToScreenSize(const Size& dip_size) {
-  // Always ceil sizes. Otherwise we may be leaving off part of the bounds.
-  return ScaleToCeiledSize(dip_size, GetDPIScale());
-}
+namespace win {
 
 int GetSystemMetricsInDIP(int metric) {
   // The system metrics always reflect the system DPI, not whatever scale we've