Fixed failing content_browsertests when async wheel events is on.

content/browser/site_per_process_browsertest.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/site_per_process_browsertest.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 46 matching lines @@
 #include "content/common/view_messages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/interstitial_page_delegate.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "content/public/common/browser_side_navigation_policy.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/content_browser_test_utils.h"
 #include "content/public/test/navigation_handle_observer.h"
 #include "content/public/test/test_frame_navigation_observer.h"
 #include "content/public/test/test_navigation_observer.h"
 #include "content/public/test/test_utils.h"
 #include "content/shell/browser/shell.h"
 #include "content/test/content_browser_test_utils_internal.h"
@@ skipping 5607 matching lines @@
     SendMouseWheel(pos);
 
     // Expect both wheel and scroll handlers to fire.
     EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
     EXPECT_EQ("\"wheel: 1\"", reply);
     EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
     EXPECT_EQ("\"scroll: 1\"", reply);
 
     SendMouseWheel(pos);
 
-    // This time only the wheel handler fires, since it prevent defaults on
-    // even numbered scrolls.
+    // If async_wheel_events is disabled, this time only the wheel handler
+    // fires, since even numbered scrolls are prevent-defaulted. If it is
+    // enabled, then this wheel event will be sent non-blockingly and won't be
+    // cancellable.
     EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
     EXPECT_EQ("\"wheel: 2\"", reply);
+    if (base::FeatureList::IsEnabled(features::kAsyncWheelEvents)) {
+      EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
+      EXPECT_EQ("\"scroll: 2\"", reply);
+    }
 
     SendMouseWheel(pos);
 
     // Odd number of wheels, expect both wheel and scroll handlers to fire
     // again.
     EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
     EXPECT_EQ("\"wheel: 3\"", reply);
     EXPECT_TRUE(msg_queue.WaitForMessage(&reply));
     EXPECT_EQ("\"scroll: 3\"", reply);
   }
@@ skipping 4771 matching lines @@
 
   // The new tab's grandchild frame should reuse the b.com process.
   EXPECT_EQ(root->child_at(0)->current_frame_host()->GetProcess(),
             new_shell_root->child_at(0)
                 ->child_at(0)
                 ->current_frame_host()
                 ->GetProcess());
 }
 
 }  // namespace content