PushEvent.data should be NULL for empty payloads

PushEvent.data should be NULL for empty payloads

There was code in the PushEvent that would create an empty data object
even when no data was available. Remove it, and add an end-to-end test.

BUG=593454
Review URL: https://codereview.chromium.org/1784583002

Cr-Commit-Position: refs/heads/master@{#380258}
(cherry picked from commit 72d7385fd0dfbd77ee41dd53cb0ef7ac16d118d7)

Committed: https://chromium.googlesource.com/chromium/src/+/0ca7be84ec95b002d722b1c46acdc9d0e76242b1

[Peter Beverloo, 2016-03-11 17:55:47]

Description was changed from

==========
PushEvent.data should be NULL for empty payloads

There was code in the PushEvent that would create an empty data object
even when no data was available. Remove it, and add an end-to-end test.

BUG=593454

Review URL: https://codereview.chromium.org/1784583002

Cr-Commit-Position: refs/heads/master@{#380258}
(cherry picked from commit 72d7385fd0dfbd77ee41dd53cb0ef7ac16d118d7)
==========

to

==========
PushEvent.data should be NULL for empty payloads

There was code in the PushEvent that would create an empty data object
even when no data was available. Remove it, and add an end-to-end test.

BUG=593454

Review URL: https://codereview.chromium.org/1784583002

Cr-Commit-Position: refs/heads/master@{#380258}
(cherry picked from commit 72d7385fd0dfbd77ee41dd53cb0ef7ac16d118d7)

Committed:
https://chromium.googlesource.com/chromium/src/+/0ca7be84ec95b002d722b1c46acd...
==========

[Peter Beverloo, 2016-03-11 17:55:49]

Committed patchset #1 (id:1) manually as
0ca7be84ec95b002d722b1c46acdc9d0e76242b1.