[Local NTP] Fix chrome://large-icon fallback when no favicon is found.

For chrome://large-icon, if no large icon is found then we get the small
favicon to extract the dominant color for fallback background. If the
favicon is missing we're supposed to have a gray background. This behavior
was broken and this CL fixes it.

BUG=467712

Review URL: https://codereview.chromium.org/1108833002

Cr-Commit-Position: refs/heads/master@{#327119}

components/favicon/core/large_icon_service.cc

@@ -45,9 +45,9 @@ void LargeIconService::RunLargeIconCallback(
     const favicon_base::FaviconRawBitmapResult& bitmap_result) {
   // If there are no bitmaps, return a result with an empty |bitmap| and a
   // default |fallback_icon_style|.
-  favicon_base::LargeIconResult result;
   if (!bitmap_result.is_valid()) {
-    callback.Run(result);
+    callback.Run(
+        favicon_base::LargeIconResult(new favicon_base::FallbackIconStyle()));
     return;
   }
 
@@ -59,7 +59,7 @@ void LargeIconService::RunLargeIconCallback(
       bitmap_result.pixel_size.width() != bitmap_result.pixel_size.height()) {
     // TODO(beaudoin): Resize the icon if it's large enough. Alternatively,
     // return it and let the HTML resize it.
-    result.fallback_icon_style.reset(new favicon_base::FallbackIconStyle());
+    favicon_base::LargeIconResult result(new favicon_base::FallbackIconStyle());
     favicon_base::SetDominantColorAsBackground(
         bitmap_result.bitmap_data, result.fallback_icon_style.get());
     callback.Run(result);
@@ -70,8 +70,7 @@ void LargeIconService::RunLargeIconCallback(
   // it.
   // TODO(beaudoin): Resize the icon if it's too large. Alternatively, return
   // it and let the HTML resize it.
-  result.bitmap = bitmap_result;
-  callback.Run(result);
+  callback.Run(favicon_base::LargeIconResult(bitmap_result));
 }
 
 }  // namespace favicon

components/favicon_base/favicon_types.cc

@@ -27,7 +27,11 @@ FaviconRawBitmapResult::~FaviconRawBitmapResult() {}
 // --------------------------------------------------------
 // LargeIconResult
 
-LargeIconResult::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() {}
 

components/favicon_base/favicon_types.h

@@ -79,7 +79,11 @@ typedef FaviconRawBitmapResult FaviconRawBitmapData;
 // either the bitmap data if the favicon database has a sufficiently large
 // favicon bitmap and the style of the fallback icon otherwise.
 struct LargeIconResult {
-  LargeIconResult();
+  explicit LargeIconResult(const FaviconRawBitmapResult& bitmap_in);
+
+  // Takes ownership of |fallback_icon_style_in|.
+  explicit LargeIconResult(FallbackIconStyle* fallback_icon_style_in);
+
   ~LargeIconResult();
 
   // The bitmap from the favicon database if the database has a sufficiently