Enable testShowJavaScriptAfterNewTabAnimation for iPad

ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm

Index: ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm
diff --git a/ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm b/ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm
index 2c7e0f421ca727a8ee935042249deaf85a96733b..d149a721e4e73a1ddd1d70c5c7ea2bbc77092e8c 100644
--- a/ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm
+++ b/ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm
@@ -555,11 +555,6 @@ - (void)testShowJavaScriptAfterNewTabAnimation {
                           @"correctly.");
 #endif
 
-  // TODO(crbug.com/711291): reenable this on tablets.
-  if (IsIPadIdiom()) {
-    EARL_GREY_TEST_DISABLED(@"Disabled for iPad.");
-  }
-
   // Load the test page with a link to kOnLoadAlertURL and long tap on the link.
   [self loadPageWithLink];
   id<GREYMatcher> webViewMatcher =
@@ -573,6 +568,20 @@ - (void)testShowJavaScriptAfterNewTabAnimation {
       l10n_util::GetNSStringWithFixup(IDS_IOS_CONTENT_CONTEXT_OPENLINKNEWTAB));
   [[EarlGrey selectElementWithMatcher:newTabMatcher] performAction:grey_tap()];
 
+  // This test case requires that a dialog is presented in the onload event so
+  // that the DialogPresenter attempts to display during a new tab animation.
+  // Because presenting a dialog halts the JavaScript execution on the page,
+  // this prevents the page loaded event from being received until the alert is
+  // closed.  On iPad, this means that there is a loading indicator that
+  // continues to animate until the dialog is closed.  Disabling EarlGrey
+  // synchronization code for iPad allows the test to detect and dismiss the
+  // dialog while this animation is occurring.
+  if (IsIPadIdiom()) {
+    [[GREYConfiguration sharedInstance]
+            setValue:@(NO)
+        forConfigKey:kGREYConfigKeySynchronizationEnabled];

[baxley, 2017/04/18 23:15:31]

Should we also add the call to enable synchronization into a teardown handler? I
don't remember offhand, but synchronization may not automatically get re-enabled
at the start of the next test.

Just for the case where the test fails after synchronization is disabled.

[kkhorimoto, 2017/04/19 18:40:38]

Done.

+  }
+
   // Wait for the alert to be shown.
   NSString* alertLabel = [DialogPresenter
       localizedTitleForJavaScriptAlertFromPage:HttpServer::MakeUrl(
@@ -587,6 +596,13 @@ - (void)testShowJavaScriptAfterNewTabAnimation {
 
   // Close the alert.
   TapOK();
+
+  // Reenable synchronization on iPads now that the dialog has been dismissed.
+  if (IsIPadIdiom()) {
+    [[GREYConfiguration sharedInstance]
+            setValue:@(YES)
+        forConfigKey:kGREYConfigKeySynchronizationEnabled];
+  }
 }
 
 @end