Prioritize smaller favicons over larger ones for tabs, etc.

chrome/browser/favicon/favicon_handler.h

Index: chrome/browser/favicon/favicon_handler.h
diff --git a/chrome/browser/favicon/favicon_handler.h b/chrome/browser/favicon/favicon_handler.h
index a59e944c42e6e66b7ba81b97b05851c1de1c8a01..3e3274a548ef5f1b748a9a377c6520734eb81679 100644
--- a/chrome/browser/favicon/favicon_handler.h
+++ b/chrome/browser/favicon/favicon_handler.h
@@ -18,6 +18,7 @@
 #include "chrome/common/ref_counted_util.h"
 #include "googleurl/src/gurl.h"
 #include "ui/gfx/favicon_size.h"
+#include "ui/gfx/image/image.h"
 
 class FaviconHandlerDelegate;
 class Profile;
@@ -29,10 +30,6 @@ namespace content {
 class NavigationEntry;
 }
 
-namespace gfx {
-class Image;
-}
-
 // FaviconHandler works with FaviconTabHelper to fetch the specific type of
 // favicon.
 //
@@ -172,6 +169,22 @@ class FaviconHandler {
     history::IconType icon_type;
   };
 
+  struct FaviconCandidate {
+    FaviconCandidate();
+    ~FaviconCandidate();
+
+    FaviconCandidate(const GURL& url,
+                     const GURL& image_url,
+                     const gfx::Image& image,
+                     history::IconType icon_type);
+
+    GURL url;
+    GURL image_url;
+    gfx::Image image;
+    history::IconType icon_type;
+  };
+  typedef std::vector<FaviconCandidate> FaviconCandidates;
+
   // See description above class for details.
   void OnFaviconDataForInitialURL(FaviconService::Handle handle,
                                   history::FaviconData favicon);
@@ -195,8 +208,10 @@ class FaviconHandler {
                        history::IconType icon_type,
                        const FaviconTabHelper::ImageDownloadCallback& callback);
 
-  // Sets the image data for the favicon. This is invoked asynchronously after
-  // we request the TabContents to download the favicon.
+  // Once all candidates are download, this picks one and calls SetFavicon().
+  void SetFaviconFromCandidates();
+
+  // Sets the image data for the favicon.
   void SetFavicon(const GURL& url,
                   const GURL& icon_url,
                   const gfx::Image& image,
@@ -211,8 +226,8 @@ class FaviconHandler {
   void UpdateFavicon(content::NavigationEntry* entry, const gfx::Image* image);
 
   // If the image is not already at its preferred size, scales the image such
-  // that either the width and/or height is 16 pixels wide. Does nothing if the
-  // image is empty.
+  // that either the width and/or height == gfx::kFaviconSize. Does nothing if
+  // the image is empty.
   gfx::Image ResizeFaviconIfNeeded(const gfx::Image& image);
 
   void FetchFaviconInternal();
@@ -267,6 +282,9 @@ class FaviconHandler {
   // This handler's delegate.
   FaviconHandlerDelegate* delegate_;  // weak
 
+  // Vector of favicon candidates.
+  FaviconCandidates favicon_candidates_;
+
   DISALLOW_COPY_AND_ASSIGN(FaviconHandler);
 };