Don't request missing favicon on every page request.

content/renderer/fetchers/multi_resolution_image_resource_fetcher.h

Index: content/renderer/fetchers/multi_resolution_image_resource_fetcher.h
diff --git a/content/renderer/fetchers/multi_resolution_image_resource_fetcher.h b/content/renderer/fetchers/multi_resolution_image_resource_fetcher.h
index 925eed25a694c96c03d0ca5432c8b0376cf0ed67..3e7c326b496564ba49a9fc430af3c52fbbabe5e2 100644
--- a/content/renderer/fetchers/multi_resolution_image_resource_fetcher.h
+++ b/content/renderer/fetchers/multi_resolution_image_resource_fetcher.h
@@ -37,6 +37,9 @@ class MultiResolutionImageResourceFetcher{
   // Unique identifier for the request.
   int id() const { return id_; }
 
+  // HTTP status code upon fetch completion.
+  int http_status_code() const { return http_status_code_; }
+
  private:
   // ResourceFetcher::Callback. Decodes the image and invokes callback_.
   void OnURLFetchComplete(const WebKit::WebURLResponse& response,
@@ -47,6 +50,9 @@ class MultiResolutionImageResourceFetcher{
   // Unique identifier for the request.
   const int id_;
 
+  // HTTP status code upon fetch completion.
+  int http_status_code_;
+
   // URL of the image.
   const GURL image_url_;