[VK] Re-enable end to end test.

No changes were made to the test. Last time, it was broken on
chromeos MSAN. I ran the MSAN try bots several times and they
all pass, so I assume that the problem has been fixed.

Will revert if this is still broken.

TBR=rdevlin.cronin@chromium.org

Bug: 515596
Change-Id: Icfdf04efa9650848d532bb105a33bad9b55cbe1a
Reviewed-on: https://chromium-review.googlesource.com/1113704
Commit-Queue: Darren Shen <shend@chromium.org>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571816}

chrome/browser/chromeos/extensions/default_keyboard_extension_browser_test.cc

@@ -157,9 +157,7 @@ IN_PROC_BROWSER_TEST_F(DefaultKeyboardExtensionBrowserTest, IsKeyboardLoaded) {
   ASSERT_TRUE(loaded);
 }
 
-// Disabled; http://crbug.com/515596
-IN_PROC_BROWSER_TEST_F(DefaultKeyboardExtensionBrowserTest,
-                       DISABLED_EndToEndTest) {
+IN_PROC_BROWSER_TEST_F(DefaultKeyboardExtensionBrowserTest, EndToEndTest) {
   // Get the virtual keyboard's WebContents.
   content::WebContents* keyboard_wc = GetKeyboardWebContents(kExtensionId);
   ASSERT_TRUE(keyboard_wc);