Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac) (Merge to M56)

Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac)

When the tab's RenderWidgetHostView is nullptr, we cannot and should not select any
RenderWidgetHosts for a drag destination. Therefore, in response to draggingEntered
we should return no operation.

This CL will fix that issue as well as making RenderWidgetHostInputEventRouter::GetRenderWidgetHostAtPoint()
handle nullptr |root_view| by returning nullptr.

BUG=670645
NOTRY=true
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2547213002
Cr-Commit-Position: refs/heads/master@{#436146}
(cherry picked from commit 5190330169f1e6c1d8418e6bcc0499fdc99ec287)

[EhsanK, 2016-12-07 00:51:00]

Description was changed from

==========
Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac)

When the tab's RenderWidgetHostView is nullptr, we cannot and should not select
any
RenderWidgetHosts for a drag destination. Therefore, in response to
draggingEntered
we should return no operation.

This CL will fix that issue as well as making
RenderWidgetHostInputEventRouter::GetRenderWidgetHostAtPoint()
handle nullptr |root_view| by returning nullptr.

BUG=670645

Review-Url: https://codereview.chromium.org/2547213002
Cr-Commit-Position: refs/heads/master@{#436146}
(cherry picked from commit 5190330169f1e6c1d8418e6bcc0499fdc99ec287)
==========

to

==========
Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac)

When the tab's RenderWidgetHostView is nullptr, we cannot and should not select
any
RenderWidgetHosts for a drag destination. Therefore, in response to
draggingEntered
we should return no operation.

This CL will fix that issue as well as making
RenderWidgetHostInputEventRouter::GetRenderWidgetHostAtPoint()
handle nullptr |root_view| by returning nullptr.

BUG=670645
NOTRY=true
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2547213002
Cr-Commit-Position: refs/heads/master@{#436146}
(cherry picked from commit 5190330169f1e6c1d8418e6bcc0499fdc99ec287)
==========

[EhsanK, 2016-12-07 00:51:00]

ekaramad@chromium.org changed reviewers:
+ avi@chromium.org

[EhsanK, 2016-12-07 05:33:19]

ptal.

[Avi (use Gerrit), 2016-12-07 05:34:26]

lgtm

[EhsanK, 2016-12-07 05:36:56]

The CQ bit was checked by ekaramad@chromium.org

[commit-bot: I haz the power, 2016-12-07 05:37:14]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-07 05:41:07]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481089016198120, "parent_rev":
"6287952d5e7a955a940ab30c312abcde77fcdde6", "commit_rev":
"e636749b59db5188c3657bc0277e294412528334"}

[commit-bot: I haz the power, 2016-12-07 05:42:06]

Description was changed from

==========
Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac)

When the tab's RenderWidgetHostView is nullptr, we cannot and should not select
any
RenderWidgetHosts for a drag destination. Therefore, in response to
draggingEntered
we should return no operation.

This CL will fix that issue as well as making
RenderWidgetHostInputEventRouter::GetRenderWidgetHostAtPoint()
handle nullptr |root_view| by returning nullptr.

BUG=670645
NOTRY=true
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2547213002
Cr-Commit-Position: refs/heads/master@{#436146}
(cherry picked from commit 5190330169f1e6c1d8418e6bcc0499fdc99ec287)
==========

to

==========
Cancel drag operation when the tab RenderWidgetHostView does not exist (Mac)

When the tab's RenderWidgetHostView is nullptr, we cannot and should not select
any
RenderWidgetHosts for a drag destination. Therefore, in response to
draggingEntered
we should return no operation.

This CL will fix that issue as well as making
RenderWidgetHostInputEventRouter::GetRenderWidgetHostAtPoint()
handle nullptr |root_view| by returning nullptr.

BUG=670645
NOTRY=true
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2547213002
Cr-Commit-Position: refs/heads/master@{#436146}
(cherry picked from commit 5190330169f1e6c1d8418e6bcc0499fdc99ec287)
==========

[commit-bot: I haz the power, 2016-12-07 05:42:06]

Committed patchset #1 (id:1)