chrome/android: Consume down events for mouse drag gesture.

chrome/android: Consume down events for mouse drag gesture.

Mouse drag gestures on android are delivered using a stream of
ACTION_MOVE events. If the view does not consume the ACTION_DOWN event
that starts the gesture, it will not receive the following move events.

Consume this event in the EventForwarder to ensure the ContentView gets
the complete gesture.

BUG=714845
Review-Url: https://codereview.chromium.org/2842823002
Cr-Commit-Position: refs/heads/master@{#467780}
(cherry picked from commit 6bc101ebf27a7a56f28d5264aed265ec43a8db45)

Review-Url: https://codereview.chromium.org/2851473006 .
Cr-Commit-Position: refs/branch-heads/3071@{#276}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/1c0d3e95679659c1b01785b9fc666aa9a8de0431

[Khushal, 2017-04-27 22:40:55]

Description was changed from

==========
chrome/android: Consume down events for mouse drag gesture.

Mouse drag gestures on android are delivered using a stream of
ACTION_MOVE events. If the view does not consume the ACTION_DOWN event
that starts the gesture, it will not receive the following move events.

Consume this event in the EventForwarder to ensure the ContentView gets
the complete gesture.

BUG=714845

Review-Url: https://codereview.chromium.org/2842823002
Cr-Commit-Position: refs/heads/master@{#467780}
(cherry picked from commit 6bc101ebf27a7a56f28d5264aed265ec43a8db45)
==========

to

==========
chrome/android: Consume down events for mouse drag gesture.

Mouse drag gestures on android are delivered using a stream of
ACTION_MOVE events. If the view does not consume the ACTION_DOWN event
that starts the gesture, it will not receive the following move events.

Consume this event in the EventForwarder to ensure the ContentView gets
the complete gesture.

BUG=714845

Review-Url: https://codereview.chromium.org/2842823002
Cr-Commit-Position: refs/heads/master@{#467780}
(cherry picked from commit 6bc101ebf27a7a56f28d5264aed265ec43a8db45)

Review-Url: https://codereview.chromium.org/2851473006 .
Cr-Commit-Position: refs/branch-heads/3071@{#276}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/1c0d3e95679659c1b01785b9fc66...
==========

[Khushal, 2017-04-27 22:40:56]

Committed patchset #1 (id:1) manually as
1c0d3e95679659c1b01785b9fc666aa9a8de0431 (tree was closed).