Explicitly suppress scrolling for wheel events that will trigger zooming

content/browser/web_contents/web_contents_impl_unittest.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 "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/browser/frame_host/cross_site_transferring_request.h"
 #include "content/browser/frame_host/interstitial_page_impl.h"
 #include "content/browser/frame_host/navigation_entry_impl.h"
 #include "content/browser/media/audio_stream_monitor.h"
@@ skipping 2458 matching lines @@
       new ContentsZoomChangedDelegate());
   contents()->SetDelegate(delegate.get());
 
   int modifiers = 0;
   // Verify that normal mouse wheel events do nothing to change the zoom level.
   blink::WebMouseWheelEvent event =
       SyntheticWebMouseWheelEventBuilder::Build(0, 1, modifiers, false);
   EXPECT_FALSE(contents()->HandleWheelEvent(event));
   EXPECT_EQ(0, delegate->GetAndResetContentsZoomChangedCallCount());
 
   modifiers = WebInputEvent::ShiftKey | WebInputEvent::AltKey;

[Rick Byers, 2014/12/18 15:18:14]

nit: set the Ctrl modifier here too (to verify that the modifier alone isn't
enough to change behavior).

[lanwei, 2014/12/19 02:55:44]

Done.

   event = SyntheticWebMouseWheelEventBuilder::Build(0, 1, modifiers, false);
   EXPECT_FALSE(contents()->HandleWheelEvent(event));
   EXPECT_EQ(0, delegate->GetAndResetContentsZoomChangedCallCount());
 
   // But whenever the ctrl modifier is applied, they can increase/decrease zoom.

[Rick Byers, 2014/12/18 15:18:14]

nit: add "with canScroll=false" to this comment.

[lanwei, 2014/12/19 02:55:44]

Done.

   // Except on MacOS where we never want to adjust zoom with mousewheel.
   modifiers = WebInputEvent::ControlKey;
   event = SyntheticWebMouseWheelEventBuilder::Build(0, 1, modifiers, false);
+  event.canScroll = false;
   bool handled = contents()->HandleWheelEvent(event);
 #if defined(OS_MACOSX)
   EXPECT_FALSE(handled);
   EXPECT_EQ(0, delegate->GetAndResetContentsZoomChangedCallCount());
 #else
   EXPECT_TRUE(handled);
   EXPECT_EQ(1, delegate->GetAndResetContentsZoomChangedCallCount());
   EXPECT_TRUE(delegate->last_zoom_in());
 #endif
 
   modifiers = WebInputEvent::ControlKey | WebInputEvent::ShiftKey |
       WebInputEvent::AltKey;
   event = SyntheticWebMouseWheelEventBuilder::Build(2, -5, modifiers, false);
+  event.canScroll = false;
   handled = contents()->HandleWheelEvent(event);
 #if defined(OS_MACOSX)
   EXPECT_FALSE(handled);
   EXPECT_EQ(0, delegate->GetAndResetContentsZoomChangedCallCount());
 #else
   EXPECT_TRUE(handled);
   EXPECT_EQ(1, delegate->GetAndResetContentsZoomChangedCallCount());
   EXPECT_FALSE(delegate->last_zoom_in());
 #endif
 
@@ skipping 274 matching lines @@
 
   // Destroy the remote player. No power save blockers should remain.
   rfh->OnMessageReceived(
       FrameHostMsg_MediaPausedNotification(0, kPlayerRemoteId));
   EXPECT_FALSE(contents()->has_video_power_save_blocker_for_testing());
   EXPECT_FALSE(contents()->has_audio_power_save_blocker_for_testing());
 }
 #endif
 
 }  // namespace content