Small cleanup to extension function registration to avoid scattered definitions.

chrome/browser/extensions/execute_code_in_tab_function.h

Index: chrome/browser/extensions/execute_code_in_tab_function.h
diff --git a/chrome/browser/extensions/execute_code_in_tab_function.h b/chrome/browser/extensions/execute_code_in_tab_function.h
index 5ea91e6bb6e4fe552bfac88e5e588691981c7239..8215fd26922fc3493dc381080da78560787a28c4 100755
--- a/chrome/browser/extensions/execute_code_in_tab_function.h
+++ b/chrome/browser/extensions/execute_code_in_tab_function.h
@@ -46,4 +46,12 @@ class ExecuteCodeInTabFunction : public AsyncExtensionFunction,
   ExtensionResource resource_;
 };
 
+class TabsExecuteScriptFunction : public ExecuteCodeInTabFunction {
+  DECLARE_EXTENSION_FUNCTION_NAME("tabs.executeScript")
+};
+
+class TabsInsertCSSFunction : public ExecuteCodeInTabFunction {
+  DECLARE_EXTENSION_FUNCTION_NAME("tabs.insertCSS")
+};
+
 #endif  // CHROME_BROWSER_EXTENSIONS_EXECUTE_CODE_IN_TAB_FUNCTION_H__