Add schema chrome-extension-resource:// for extension resources

chrome/common/extensions/extension_file_util.h

Index: chrome/common/extensions/extension_file_util.h
diff --git a/chrome/common/extensions/extension_file_util.h b/chrome/common/extensions/extension_file_util.h
index 1ab3f07678dbcdb6878df314410ee1d26e1a4a5e..1ad1120c6dd16da4811a12798d1eb1cf271d565f 100644
--- a/chrome/common/extensions/extension_file_util.h
+++ b/chrome/common/extensions/extension_file_util.h
@@ -100,6 +100,10 @@ bool CheckForIllegalFilenames(const FilePath& extension_path,
 // Get a relative file path from a chrome-extension:// URL.
 FilePath ExtensionURLToRelativeFilePath(const GURL& url);
 
+// Get a full file path from a chrome-extension-resource:// URL, If the URL
+// points a file outside of root, this function will return empty FilePath.
+FilePath ExtensionResourceURLToFilePath(const GURL& url, const FilePath& root);
+
 // Get a path to a temp directory for unpacking an extension.
 // This is essentially PathService::Get(chrome::DIR_USER_DATA_TEMP, ...),
 // with a histogram that allows us to understand why it is failing.