Save large icons to a new LARGE_ICON type

components/favicon_base/favicon_types.h

 // 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.
 
 #ifndef COMPONENTS_FAVICON_BASE_FAVICON_TYPES_H_
 #define COMPONENTS_FAVICON_BASE_FAVICON_TYPES_H_
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
 namespace favicon_base {
 
 struct FallbackIconStyle;
 
 typedef int64 FaviconID;
 
 // Defines the icon types. They are also stored in icon_type field of favicons
 // table.
+//
 // The values of the IconTypes are used to select the priority in which favicon
 // data is returned in HistoryBackend and ThumbnailDatabase. Data for the
 // largest IconType takes priority if data for multiple IconTypes is available.
+//
+// Note that LARGE_ICON is a virtual icon type. In desktop environments, where
+// favicons are small by default and larger touch icons are not the norm, it
+// denotes the largest available icon the determined to be available. The

[beaudoin, 2015/05/05 00:54:00]

NIT: icon determined to be available

[Roger McFarlane (Chromium), 2015/05/05 15:09:47]

Done.

+// underlying icon may have originated as a large FAVICON, a TOUCH_ICON, or a
+// TOUCH_PRECOMPOSED_ICON. In mobile environments, larger sized icons are
+// generally captured by default, so additional LARGE_ICON tagged icons are not
+// stored. The LARGE_ICON type tag is only applied at the storage and query
+// layers; icons are recognized using their true underlying type and, if it is
+// determined that a large icon is desired but will not otherwise be captured,
+// the backend selects the best candidate and saves it using the LARGE_ICON
+// type. When querying for a large icon, all potential icon types are
+// considered, and the returned results are evaluted based on the requested
+// size.
 enum IconType {
   INVALID_ICON = 0x0,
   FAVICON = 1 << 0,
   TOUCH_ICON = 1 << 1,
-  TOUCH_PRECOMPOSED_ICON = 1 << 2
+  TOUCH_PRECOMPOSED_ICON = 1 << 2,
+  LARGE_ICON = 1 << 3
 };
 
 // Defines a gfx::Image of size desired_size_in_dip composed of image
 // representations for each of the desired scale factors.
 struct FaviconImageResult {
   FaviconImageResult();
   ~FaviconImageResult();
 
   // The resulting image.
   gfx::Image image;
@@ skipping 51 matching lines @@
   FaviconRawBitmapResult bitmap;
 
   // The fallback icon style if a sufficiently large icon isn't available. This
   // uses the dominant color of a smaller icon as the background if available.
   scoped_ptr<FallbackIconStyle> fallback_icon_style;
 };
 
 }  // namespace favicon_base
 
 #endif  // COMPONENTS_FAVICON_BASE_FAVICON_TYPES_H_