Explicitly suppress scrolling for wheel events that will trigger zooming

Explicitly suppress scrolling for wheel events that will trigger zooming

This is a modified version of issue 739013008 (https://codereview.chromium.org/739013008/),
which has been reverted because it broke layout tests that use wheel events.
The previous patch made InitMouseWheelEvent return too early before
the event has been setup correctly. The previous patch was committed because
it only broke the webkit unittests, which will not be tested at this
time since it is a Chrome side change.

We added a flag in Blink to decide if Ctrl-wheel-scroll should scroll
or zoom, and now we use this flag in chromium code.

This patch is part of a series:

patch #1: https://codereview.chromium.org/759073002
patch #2: This CL
patch #3: https://codereview.chromium.org/768443002

BUG=397027, 378755
Committed: https://crrev.com/a93644fa5e6b9741444af2a29bf1069c7fc7ebfb
Cr-Commit-Position: refs/heads/master@{#312467}

[lanwei, 2015-01-14 16:49:54]

lanwei@chromium.org changed reviewers:
+ jdduke@chromium.org, rbyers@chromium.org, tdresser@chromium.org

[tdresser, 2015-01-14 18:45:25]

On 2015/01/14 18:05:52, lanwei wrote:

Change in event_sender.cc LGTM!

[jdduke (slow), 2015-01-14 18:49:55]

input/ changes lgtm.

https://codereview.chromium.org/835523006/diff/20001/content/common/input/web...
File content/common/input/web_input_event_traits_unittest.cc (right):

https://codereview.chromium.org/835523006/diff/20001/content/common/input/web...
content/common/input/web_input_event_traits_unittest.cc:186: mouseWheel0 =
CreateMouseWheel(1, 1, true);
Nit: chromium_underscore_case :)

[Rick Byers, 2015-01-15 02:18:36]

PS#1 reflects what was previously landed, right (i.e. the only change from that
is in event_sender.cc)?  LGTM assuming that's the case.

[lanwei, 2015-01-16 16:29:13]

On 2015/01/15 02:18:36, Rick Byers wrote:
> PS#1 reflects what was previously landed, right (i.e. the only change from
that
> is in event_sender.cc)?  LGTM assuming that's the case.

Yes, I only changed the event_sender.cc file.

[lanwei, 2015-01-16 16:34:03]

lanwei@chromium.org changed reviewers:
+ sievers@chromium.org

[lanwei, 2015-01-16 16:34:04]

sievers@chromium.org: Please review changes in 

Can you please take a look at this issue which is the almost the same as
https://codereview.chromium.org/739013008/, the only thing that I changed is the
event_sender.cc file?

Thank you.

https://codereview.chromium.org/835523006/diff/20001/content/common/input/web...
File content/common/input/web_input_event_traits_unittest.cc (right):

https://codereview.chromium.org/835523006/diff/20001/content/common/input/web...
content/common/input/web_input_event_traits_unittest.cc:186: mouseWheel0 =
CreateMouseWheel(1, 1, true);
On 2015/01/14 18:49:55, jdduke wrote:
> Nit: chromium_underscore_case :)

Done.

[no sievers, 2015-01-20 20:27:48]

lgtm

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
File content/browser/renderer_host/input/input_router_impl.cc (right):

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
content/browser/renderer_host/input/input_router_impl.cc:141: // event and so
coalescing shouldn't occur.  Note that the
Should there be a DCHECK() for this assumption?

[lanwei, 2015-01-21 03:17:32]

The CQ bit was checked by lanwei@chromium.org

[lanwei, 2015-01-21 03:17:40]

The CQ bit was unchecked by lanwei@chromium.org

[Rick Byers, 2015-01-21 15:49:13]

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
File content/browser/renderer_host/input/input_router_impl.cc (right):

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
content/browser/renderer_host/input/input_router_impl.cc:141: // event and so
coalescing shouldn't occur.  Note that the
On 2015/01/20 20:27:48, sievers wrote:
> Should there be a DCHECK() for this assumption?

Good idea, I think we _should_ be able to say this:

DCHECK((wheel_event.hasPreciseDeltas && !wheel_event.canScroll) ==
wheel_event.synthesized_from_pinch)

Let's try and see if any tests trigger it :-)

[lanwei, 2015-01-21 21:23:59]

The CQ bit was checked by lanwei@chromium.org

[commit-bot: I haz the power, 2015-01-21 21:25:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/835523006/60001

[commit-bot: I haz the power, 2015-01-21 22:01:10]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-01-21 22:02:05]

Patchset 4 (id:??) landed as
https://crrev.com/a93644fa5e6b9741444af2a29bf1069c7fc7ebfb
Cr-Commit-Position: refs/heads/master@{#312467}

[lanwei, 2015-02-04 03:25:58]

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
File content/browser/renderer_host/input/input_router_impl.cc (right):

https://codereview.chromium.org/835523006/diff/40001/content/browser/renderer...
content/browser/renderer_host/input/input_router_impl.cc:141: // event and so
coalescing shouldn't occur.  Note that the
On 2015/01/20 20:27:48, sievers wrote:
> Should there be a DCHECK() for this assumption?

Done.