Add ExecuteJavaScriptForTest and make all tests use it

chrome/browser/download/download_browsertest.cc

Index: chrome/browser/download/download_browsertest.cc
diff --git a/chrome/browser/download/download_browsertest.cc b/chrome/browser/download/download_browsertest.cc
index 3f59c51e9efc86d3ddb03baa372d2216bfc035f1..d73dc34f2a7de2ff5d7913ff3582ab971d8d7801 100644
--- a/chrome/browser/download/download_browsertest.cc
+++ b/chrome/browser/download/download_browsertest.cc
@@ -2237,7 +2237,8 @@ IN_PROC_BROWSER_TEST_F(DownloadTest, SavePageNonHTMLViaPost) {
           &web_contents->GetController()));
   content::RenderFrameHost* render_frame_host = web_contents->GetMainFrame();
   ASSERT_TRUE(render_frame_host != NULL);
-  render_frame_host->ExecuteJavaScript(base::ASCIIToUTF16("SubmitForm()"));
+  render_frame_host->ExecuteJavaScriptForTests(
+      base::ASCIIToUTF16("SubmitForm()"));
   observer.Wait();
   EXPECT_EQ(jpeg_url, web_contents->GetURL());