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

components/favicon_base/favicon_types.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/favicon_base/favicon_types.h"
 
 #include "components/favicon_base/fallback_icon_style.h"
 
 namespace favicon_base {
 
@@ skipping 20 matching lines @@
 // LargeIconResult
 
 LargeIconResult::LargeIconResult(const FaviconRawBitmapResult& bitmap_in)
     : bitmap(bitmap_in) {}
 
 LargeIconResult::LargeIconResult(FallbackIconStyle* fallback_icon_style_in)
     : fallback_icon_style(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
 
 LargeIconImageResult::LargeIconImageResult(const gfx::Image& image_in)
     : image(image_in) {}
 
 LargeIconImageResult::LargeIconImageResult(
     FallbackIconStyle* fallback_icon_style_in)
     : fallback_icon_style(fallback_icon_style_in) {}
 
 LargeIconImageResult::~LargeIconImageResult() {}
 
 }  // namespace favicon_base