Call EnableNonClientDpiScaling

ui/views/win/hwnd_message_handler.h

Index: ui/views/win/hwnd_message_handler.h
diff --git a/ui/views/win/hwnd_message_handler.h b/ui/views/win/hwnd_message_handler.h
index 622696f2f30f52a54037eb7dedf2b826bbbb7602..7e47c4c2d1856ffab0c9239398be7b92f36c9666 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -411,6 +411,7 @@ class VIEWS_EXPORT HWNDMessageHandler :
     CR_MSG_WM_MOVE(OnMove)
     CR_MSG_WM_MOVING(OnMoving)
     CR_MSG_WM_NCCALCSIZE(OnNCCalcSize)
+    CR_MSG_WM_NCCREATE(OnNCCreate)
     CR_MSG_WM_NCHITTEST(OnNCHitTest)
     CR_MSG_WM_NCPAINT(OnNCPaint)
     CR_MSG_WM_NOTIFY(OnNotify)
@@ -462,6 +463,7 @@ class VIEWS_EXPORT HWNDMessageHandler :
   void OnMoving(UINT param, const RECT* new_bounds);
   LRESULT OnNCActivate(UINT message, WPARAM w_param, LPARAM l_param);
   LRESULT OnNCCalcSize(BOOL mode, LPARAM l_param);
+  LRESULT OnNCCreate(LPCREATESTRUCT lpCreateStruct);
   LRESULT OnNCHitTest(const gfx::Point& point);
   void OnNCPaint(HRGN rgn);
   LRESULT OnNCUAHDrawCaption(UINT message, WPARAM w_param, LPARAM l_param);
@@ -577,6 +579,9 @@ class VIEWS_EXPORT HWNDMessageHandler :
   // The current DPI.
   int dpi_;
 
+  // Whether EnableNonClientDpiScaling was called successfully with this window.

[sky, 2016/12/14 02:42:41]

Can you describe what that means (folks looking at this class won't necessarily
know what this means).

[robliao, 2016/12/14 18:50:19]

Done.

  // Whether EnableNonClientDpiScaling was called successfully with this window.
  // This flag exists because EnableNonClientDpiScaling must be called during
  // WM_NCCREATE and EnableChildWindowDpiMessage is called after window
  // creation. We don't want to call both, so this helps us determine if a call
  // to EnableChildWindowDpiMessage is necessary.

[sky, 2016/12/14 18:54:24]

Excellent! But I was hoping you would describe what EnableNonClientDpiScaling()
does. But I'm ok with the improved description here.

[robliao, 2016/12/14 19:03:18]

EnableNonClientDpiScaling is a public Windows function; I defer to MSDN for that
(https://msdn.microsoft.com/en-us/library/windows/desktop/mt748621(v=vs.85).aspx)

+  bool called_enable_non_client_dpi_scaling_;
+
   // Event handling ------------------------------------------------------------
 
   // The flags currently being used with TrackMouseEvent to track mouse