Fix Jumplist favicons to have high resolution in HDPI Windows displays

components/favicon/core/favicon_service.h

Index: components/favicon/core/favicon_service.h
diff --git a/components/favicon/core/favicon_service.h b/components/favicon/core/favicon_service.h
index 9585934169f21c7407aff49adb9fa1718a3a30af..06607b819ba8317167c119131563a87086eb5f63 100644
--- a/components/favicon/core/favicon_service.h
+++ b/components/favicon/core/favicon_service.h
@@ -19,6 +19,7 @@
 #include "components/favicon_base/favicon_types.h"
 #include "components/favicon_base/favicon_usage_data.h"
 #include "components/keyed_service/core/keyed_service.h"
+#include "ui/gfx/favicon_size.h"
 
 class GURL;
 
@@ -94,15 +95,17 @@ class FaviconService : public KeyedService {
   // (e.g. <http://www.google.com>)
 
   // Requests the favicon for the page at |page_url| of type
-  // favicon_base::FAVICON and of size gfx::kFaviconSize. The returned
-  // gfx::Image is populated with representations for all of the scale factors
-  // supported by the platform (e.g. MacOS). If data is unavailable for some or
-  // all of the scale factors, the bitmaps with the best matching sizes are
-  // resized.
+  // favicon_base::FAVICON and of size |faviconSize|. gfx::kFaviconSize is used
+  // by default for |faviconSize|, while gfx::kHdpiFaviconSize should be used
+  // for high DPI machines or displays. The returned gfx::Image is populated
+  // with representations for all of the scale factors supported by the platform
+  // (e.g. MacOS). If data is unavailable for some or all of the scale factors,
+  // the bitmaps with the best matching sizes are resized.
   base::CancelableTaskTracker::TaskId GetFaviconImageForPageURL(
       const GURL& page_url,
       const favicon_base::FaviconImageCallback& callback,
-      base::CancelableTaskTracker* tracker);
+      base::CancelableTaskTracker* tracker,
+      const int faviconSize = gfx::kFaviconSize);

[sky, 2017/01/31 23:28:44]

You shouldn't need to specify a size. The gfx::Image will contain multiple
images if possible so that you can grab the one appropriate based on the scale.

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

Acknowledged.

 
   // Requests the favicon for the page at |page_url| with one of |icon_types|
   // and with |desired_size_in_pixel|. |icon_types| can be any combination of