Add UI test for click-to-play.

chrome/test/automation/tab_proxy.h

Index: chrome/test/automation/tab_proxy.h
diff --git a/chrome/test/automation/tab_proxy.h b/chrome/test/automation/tab_proxy.h
index 4efbb86f9aa827b7c241a4812b09cb0ea1002a65..92a80a76e69eef5d51dc2d0e01f7f6589f10457f 100644
--- a/chrome/test/automation/tab_proxy.h
+++ b/chrome/test/automation/tab_proxy.h
@@ -375,6 +375,9 @@ class TabProxy : public AutomationResourceProxy,
   // Uses the specified encoding to override encoding of the page in the tab.
   bool OverrideEncoding(const std::string& encoding) WARN_UNUSED_RESULT;
 
+  // Loads all blocked plug-ins on the page.
+  bool LoadBlockedPlugins() WARN_UNUSED_RESULT;
+
 #if defined(OS_WIN)
   // Resizes the tab window.
   // The parent_window parameter allows a parent to be specified for the window