Add an histogram to differentiate between hang types of the renderer

Add an histogram to differentiate between hang types of the renderer

We've seen a sharp augmentation of renderer hangs on Android. This histogram is
meant to help identify the root cause of this renderer hangs, since it's
currently hard to distinguish whether this is happening during normal browsing
or during beforeunload/unload/when the page is closing.

BUG=621303
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2136173003
Cr-Commit-Position: refs/heads/master@{#406039}
(cherry picked from commit 639fdffbabc7a64ba11160c923af46b18d945650)

Committed: https://chromium.googlesource.com/chromium/src/+/8ab6a56d2377c98129cfb09de20ece3e738eb5b1

[amineer, 2016-07-18 23:41:47]

Description was changed from

==========
Add an histogram to differentiate between hang types of the renderer

We've seen a sharp augmentation of renderer hangs on Android. This histogram is
meant to help identify the root cause of this renderer hangs, since it's
currently hard to distinguish whether this is happening during normal browsing
or during beforeunload/unload/when the page is closing.

BUG=621303
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2136173003
Cr-Commit-Position: refs/heads/master@{#406039}
(cherry picked from commit 639fdffbabc7a64ba11160c923af46b18d945650)
==========

to

==========
Add an histogram to differentiate between hang types of the renderer

We've seen a sharp augmentation of renderer hangs on Android. This histogram is
meant to help identify the root cause of this renderer hangs, since it's
currently hard to distinguish whether this is happening during normal browsing
or during beforeunload/unload/when the page is closing.

BUG=621303
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2136173003
Cr-Commit-Position: refs/heads/master@{#406039}
(cherry picked from commit 639fdffbabc7a64ba11160c923af46b18d945650)

Committed:
https://chromium.googlesource.com/chromium/src/+/8ab6a56d2377c98129cfb09de20e...
==========

[amineer, 2016-07-18 23:41:50]

Committed patchset #1 (id:1) manually as
8ab6a56d2377c98129cfb09de20ece3e738eb5b1.