Fixed context menu handling for -webkit-touch-callout styled elements.

Context menu is sometimes invoked for parent elements. f.e. a link can
be a parent element of an image and even though user has pressed on the
image, context menu is still shown for link, not for image.

This CL checks -webkit-touch-callout style on element it is about to
present a menu for (which can be a parent). Before the change
-webkit-touch-callout was always checked for a parent causing system
context menu to show up.

Bug: 736480
Change-Id: I9239d75a1bfd9926dd67d1c742763c56837b0c38
Reviewed-on: https://chromium-review.googlesource.com/578215
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488423}

ios/web/web_state/js/context_menu_js_unittest.mm

@@ -204,4 +204,24 @@ TEST_F(ContextMenuJsTest, LinkOfImage) {
   }
 }
 
+// Tests context menu invoked on an image with "-webkit-touch-callout:none"
+// style and parent link.
+TEST_F(ContextMenuJsTest, LinkOfImageWithCalloutNone) {
+  // A page with an image surrounded by a link.
+  static const char image_html[] =
+      "<a href='%s'>"
+      "<img style='width:9;height:9;display:block;-webkit-touch-callout:none;'>"
+      "</a>";
+
+  // A page with a link to a destination URL.
+  LoadHtml(base::StringPrintf(image_html, "http://destination"));
+  id result = ExecuteGetElementFromPointJavaScript(5, 5);
+  NSDictionary* expected_result = @{
+    kContextMenuElementInnerText : @"",
+    kContextMenuElementReferrerPolicy : @"default",
+    kContextMenuElementHyperlink : @"http://destination/",
+  };
+  EXPECT_NSEQ(expected_result, result);
+}
+
 }  // namespace web

ios/web/web_state/js/resources/context_menu.js

@@ -76,8 +76,6 @@ goog.provide('__crWeb.contextMenu');
         continue;
       }
 
-      if (getComputedWebkitTouchCallout_(element) === 'none')
-        continue;
       // Also check element's ancestors. A bound on the level is used here to
       // avoid large overhead when no links or images are found.
       var level = 0;
@@ -94,6 +92,7 @@ goog.provide('__crWeb.contextMenu');
           return {};
         }
 
+       if (getComputedWebkitTouchCallout_(element) !== 'none') {
           if (tagName === 'a' && element.href) {
             // Found a link.
             return {
@@ -135,6 +134,7 @@ goog.provide('__crWeb.contextMenu');
             }
             return result;
           }
+        }
         element = element.parentNode;
       }
     }