Add ExecuteJavaScriptForTest and make all tests use it

chrome/browser/task_manager/task_manager_browsertest.cc

Index: chrome/browser/task_manager/task_manager_browsertest.cc
diff --git a/chrome/browser/task_manager/task_manager_browsertest.cc b/chrome/browser/task_manager/task_manager_browsertest.cc
index 5d13c532a6f1c08af84ae2eb7eca42ca61b43106..3c27c4743c0c06d82c4c245947a450330d02cb4d 100644
--- a/chrome/browser/task_manager/task_manager_browsertest.cc
+++ b/chrome/browser/task_manager/task_manager_browsertest.cc
@@ -257,7 +257,8 @@ IN_PROC_BROWSER_TEST_F(TaskManagerBrowserTest,
   tab1->GetMainFrame()->ExecuteJavaScriptWithUserGestureForTests(
       base::ASCIIToUTF16("window.open('title3.html', '_blank');"));
   // ... then immediately hang the renderer so that title3.html can't load.
-  tab1->GetMainFrame()->ExecuteJavaScript(base::ASCIIToUTF16("while(1);"));
+  tab1->GetMainFrame()->ExecuteJavaScriptForTests(
+      base::ASCIIToUTF16("while(1);"));
 
   // Blocks until a new WebContents appears.
   WebContents* tab2 = web_contents_added_observer.GetWebContents();