[Favicon] Stop caching the default favicon

chrome/browser/ui/webui/favicon_source.h

Index: chrome/browser/ui/webui/favicon_source.h
diff --git a/chrome/browser/ui/webui/favicon_source.h b/chrome/browser/ui/webui/favicon_source.h
index 0f47e0e4437800e370bfd7e76b5c3c6f4b45c6cf..ded5ce5e6531758101a4956f34e4858b6cfb5aac 100644
--- a/chrome/browser/ui/webui/favicon_source.h
+++ b/chrome/browser/ui/webui/favicon_source.h
@@ -105,12 +105,12 @@ class FaviconSource : public content::URLDataSource {
   Profile* profile_;
 
  private:
-  // Defines the allowed pixel sizes for requested favicons.
+  // Defines the pixel sizes for requested favicons.
   enum IconSize {
-    SIZE_16,
-    SIZE_32,
-    SIZE_64,
-    NUM_SIZES
+    SIZE_NOT_EXISTS = 0,
+    SIZE_16 = 16,
+    SIZE_32 = 32,
+    SIZE_64 = 64
   };
 
   // Called when favicon data is available from the history backend.
@@ -127,10 +127,6 @@ class FaviconSource : public content::URLDataSource {
 
   base::CancelableTaskTracker cancelable_task_tracker_;
 
-  // Raw PNG representations of favicons of each size to show when the favicon
-  // database doesn't have a favicon for a webpage. Indexed by IconSize values.
-  scoped_refptr<base::RefCountedMemory> default_favicons_[NUM_SIZES];
-
   // The favicon_base::IconTypes of icon that this FaviconSource handles.
   int icon_types_;