Add error description to the DidFailProvisionalLoad callback.

chrome/browser/extensions/extension_webnavigation_api.h

Index: chrome/browser/extensions/extension_webnavigation_api.h
diff --git a/chrome/browser/extensions/extension_webnavigation_api.h b/chrome/browser/extensions/extension_webnavigation_api.h
index 92d098569014de2c793d5b18834908eeee801057..cdaea53d9da02109ddc555ff99c78787949d9ec0 100644
--- a/chrome/browser/extensions/extension_webnavigation_api.h
+++ b/chrome/browser/extensions/extension_webnavigation_api.h
@@ -142,10 +142,12 @@ class ExtensionWebNavigationTabObserver : public TabContentsObserver {
       bool is_main_frame,
       const GURL& url,
       PageTransition::Type transition_type) OVERRIDE;
-  virtual void DidFailProvisionalLoad(int64 frame_id,
-                                      bool is_main_frame,
-                                      const GURL& validated_url,
-                                      int error_code) OVERRIDE;
+  virtual void DidFailProvisionalLoad(
+      int64 frame_id,
+      bool is_main_frame,
+      const GURL& validated_url,
+      int error_code,
+      const string16& error_description) OVERRIDE;
   virtual void DocumentLoadedInFrame(int64 frame_id) OVERRIDE;
   virtual void DidFinishLoad(int64 frame_id) OVERRIDE;
   virtual void TabContentsDestroyed(TabContents* tab) OVERRIDE;