Fix Aura can't provide accurate cursor hotspot info.

On Linux,  device scale factor is not set.
On Win, there is no API to offer hotspot of a cursor.
This cl addresses the above two problems.

BUG=676687

Review-Url: https://codereview.chromium.org/2605773002
Cr-Commit-Position: refs/heads/master@{#441790}

ui/base/cursor/cursor_loader_x11.cc

@@ -284,6 +284,7 @@ void CursorLoaderX11::SetPlatformCursor(gfx::NativeCursor* cursor) {
   if (*cursor == kCursorCustom)
     return;
 
+  cursor->set_device_scale_factor(scale());
   cursor->SetPlatformCursor(CursorFromId(cursor->native_type()));
 }
 

ui/base/cursor/cursors_aura.cc

@@ -239,6 +239,7 @@ bool GetCursorBitmap(const Cursor& cursor,
   cursor_loader.SetPlatformCursor(&cursor_copy);
   const std::unique_ptr<SkBitmap> cursor_bitmap(
       IconUtil::CreateSkBitmapFromHICON(cursor_copy.platform()));
+  *point = IconUtil::GetHotSpotFromHICON(cursor_copy.platform());
 #else
   int resource_id;
   if (!GetCursorDataFor(ui::CURSOR_SET_NORMAL,

ui/gfx/icon_util.cc

@@ -369,6 +369,14 @@ base::win::ScopedHICON IconUtil::CreateCursorFromDIB(const gfx::Size& icon_size,
   return base::win::ScopedHICON(CreateIconIndirect(&ii));
 }
 
+gfx::Point IconUtil::GetHotSpotFromHICON(HICON icon) {
+  ScopedICONINFO icon_info;
+  gfx::Point hotspot;
+  if (::GetIconInfo(icon, &icon_info))
+    hotspot = gfx::Point(icon_info.xHotspot, icon_info.yHotspot);
+
+  return hotspot;
+}
 SkBitmap IconUtil::CreateSkBitmapFromHICONHelper(HICON icon,
                                                  const gfx::Size& s) {
   DCHECK(icon);

ui/gfx/icon_util.h

@@ -141,6 +141,10 @@ class GFX_EXPORT IconUtil {
                                                     const void* dib_bits,
                                                     size_t dib_size);
 
+  // Given a valid HICON handle representing an icon, this function retrieves
+  // the hot spot of the icon.
+  static gfx::Point GetHotSpotFromHICON(HICON icon);
+
  private:
   // The icon format is published in the MSDN but there is no definition of
   // the icon file structures in any of the Windows header files so we need to