Context menu egtests, plus related utilities.

ios/testing/earl_grey/matchers.mm

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/testing/earl_grey/matchers.h"
+
+namespace testing {
+
+id<GREYMatcher> contextMenuItemContainingText(NSString* text) {
+  // Both tablet and phone house context menu views inside an alert controller
+  // view (on tablet that view is itself inside a popover view).
+  id<GREYMatcher> context_menu_container =
+      grey_kindOfClass(NSClassFromString(@"_UIAlertControllerView"));
+
+  return grey_allOf(grey_ancestor(context_menu_container),
+                    grey_interactable(),
+                    grey_text(text),
+                    nil);
+}
+
+id<GREYMatcher> elementToDismissContextMenu() {
+  UIUserInterfaceIdiom idiom = [[UIDevice currentDevice] userInterfaceIdiom];
+  if (idiom == UIUserInterfaceIdiomPad) {
+    // On iPad the context menu is dismissed by tapping on something
+    // that isn't the popover. The web controller container view is an easy
+    // choice, although it needs to be not-underneath the popover.
+    id<GREYMatcher> popover =
+        grey_kindOfClass(NSClassFromString(@"_UIPopoverView"));
+    return grey_allOf(grey_not(grey_ancestor(popover)),
+                      grey_kindOfClass(
+                          NSClassFromString(@"CRWWebControllerContainerView")),

[Eugene But (OOO till 7-30), 2016/08/30 18:11:04]

CRWWebControllerContainerView is a private web class. And if we change it the
test will fail. Can you avoid this dependency?

[baxley, 2016/08/31 04:25:43]

nit: grey_allOf is more efficient if the matchers with less "matches" are first?
Would grey_kindOfClass be more specific than gren_not(grey_ancestor(popover))?

It finds all the matches from the first matcher. Then it runs those through the
second, and so on.

[marq (ping after 24h), 2016/08/31 13:07:57]

Done.

[marq (ping after 24h), 2016/08/31 13:07:57]

Yep, turns out UIKit makes this very easy by labelling a view
"PopoverDismissRegion" ;-).

+                      nil);
+  } else {
+    // On iPhone the context menu is dismissed by tapping on the "Cancel" item.
+    return contextMenuItemContainingText(@"Cancel");

[Eugene But (OOO till 7-30), 2016/08/30 18:11:04]

Can this string be localized somehow?

[marq (ping after 24h), 2016/08/31 13:07:57]

Yes, now callers pass in a string; if they use localized strings, they can pass
in a localized one. web_shell doesn't, so the egstest just passes in the
hardcoded @"Cancel".

+  }
+}
+
+}  // namespace testing
+