Clean up the IconLoader.

chrome/browser/icon_loader_chromeos.cc

Index: chrome/browser/icon_loader_chromeos.cc
diff --git a/chrome/browser/icon_loader_chromeos.cc b/chrome/browser/icon_loader_chromeos.cc
index 9704f2eba05a6baac9fce6b8da34aecb52d8cf37..213dde9f3388abbfb4623a9413e582a5c50377bb 100644
--- a/chrome/browser/icon_loader_chromeos.cc
+++ b/chrome/browser/icon_loader_chromeos.cc
@@ -183,17 +183,12 @@ int IconSizeToDIPSize(IconLoader::IconSize size) {
 }  // namespace
 
 // static
-IconGroupID IconLoader::ReadGroupIDFromFilepath(
+IconLoader::IconGroup IconLoader::GroupForFilepath(
     const base::FilePath& filepath) {
   return base::ToLowerASCII(filepath.Extension());
 }
 
 // static
-bool IconLoader::IsIconMutableFromFilepath(const base::FilePath&) {
-  return false;
-}
-
-// static
 content::BrowserThread::ID IconLoader::ReadIconThreadID() {
   return content::BrowserThread::FILE;
 }