Revert "Improve the resolution of the menu item homescreen launch source metric."

Revert "Improve the resolution of the menu item homescreen launch source metric."

This reverts commit 3feb5fba279ded7c74309592bc573063de5fd28f.

Reason for revert: breaks M57 compile because this smuggles an unrelated
change from tip of tree onto M57 (which doesn't support it).

BUG=690266
Review-Url: https://codereview.chromium.org/2703213003 .
Cr-Commit-Position: refs/branch-heads/2987@{#596}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/f53b2a806f534f4195fc6873b1185aa456b1fd06

[dominickn, 2017-02-20 10:29:34]

Description was changed from

==========
Revert "Improve the resolution of the menu item homescreen launch source
metric."

This reverts commit 3feb5fba279ded7c74309592bc573063de5fd28f.

Reason for revert: breaks M57 compile because this smuggles an unrelated
change from tip of tree onto M57 (which doesn't support it).

BUG=690266
==========

to

==========
Revert "Improve the resolution of the menu item homescreen launch source
metric."

This reverts commit 3feb5fba279ded7c74309592bc573063de5fd28f.

Reason for revert: breaks M57 compile because this smuggles an unrelated
change from tip of tree onto M57 (which doesn't support it).

BUG=690266

Review-Url: https://codereview.chromium.org/2703213003 .
Cr-Commit-Position: refs/branch-heads/2987@{#596}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/f53b2a806f534f4195fc6873b118...
==========

[dominickn, 2017-02-20 10:29:36]

Committed patchset #1 (id:1) manually as
f53b2a806f534f4195fc6873b1185aa456b1fd06.