Fix Jumplist favicons to have high resolution in HDPI Windows displays

ui/gfx/favicon_size.cc

Index: ui/gfx/favicon_size.cc
diff --git a/ui/gfx/favicon_size.cc b/ui/gfx/favicon_size.cc
index d0ba48a4ccdd597f0f3e12bd77f124c276f3c425..76c839b784f8aa8dcedc374f0cf02416c2b4927d 100644
--- a/ui/gfx/favicon_size.cc
+++ b/ui/gfx/favicon_size.cc
@@ -8,6 +8,8 @@ namespace gfx {
 
 const int kFaviconSize = 16;
 
+const int kHdpiFaviconSize = 32;

[sky, 2017/01/31 23:28:45]

This isn't entirely accurate. High dpi generally means any scale other than 1x.
Don't add this constant here.

[chengx, 2017/02/02 20:52:58]

Acknowledged.

+
 void CalculateFaviconTargetSize(int* width, int* height) {
   if (*width > kFaviconSize || *height > kFaviconSize) {
     // Too big, resize it maintaining the aspect ratio.