[NTP Tiles] Fetch missing MostLikely tiles from a Google server

components/favicon_base/favicon_types.cc

Index: components/favicon_base/favicon_types.cc
diff --git a/components/favicon_base/favicon_types.cc b/components/favicon_base/favicon_types.cc
index b03f0ecd4ae4330ef4bc176c0e7d31945c272ea9..b32131120987da7a90e00153cba7237643ad1a52 100644
--- a/components/favicon_base/favicon_types.cc
+++ b/components/favicon_base/favicon_types.cc
@@ -38,6 +38,14 @@ LargeIconResult::LargeIconResult(FallbackIconStyle* fallback_icon_style_in)
 
 LargeIconResult::~LargeIconResult() {}
 
+bool LargeIconResult::is_empty() const {

[pkotwicz, 2017/05/12 07:40:38]

I think that the implementation should be in the caller. i.e.
IconCacherImpl::OnGetLargeIconOrFallbackStyleFinished()

This function isn't really checking for empty. It wants to know whether:
1) LargeIconResult uses a fallback style
2) The fallback style which is used is the default fallback style

(LargeIconService should never return a LargeIconResult with an invalid
FaviconRawBitmapResult)

LargeIconResult::is_default() would be a better name for the function 

For the sake of clarity my preference is for the implementation to be in the
caller for now

[jkrcal, 2017/05/12 11:49:02]

The reason I put it here because something similar is done in
ContentSuggestionsService::OnGetFaviconFromCacheFinished() and I want to have
clean code and avoid duplicating such helper functions.

Anyway, I think it more belongs to the LargeIconService (because it is the
service that in the end decides under which conditions the image can get
fetched).

So I follow your preference, put it into the caller, now and postpone the
potential move of this helper into LargeIconService for a later CL.

+  if (bitmap.is_valid())
+    return false;
+  if (fallback_icon_style && !fallback_icon_style->is_default_background_color)
+    return false;
+  return true;
+}
+
 // --------------------------------------------------------
 // LargeIconImageResult