DevTools: More precise CPU throttling rate on Linux

DevTools: More precise CPU throttling rate on Linux

There seems to be some delay during POSIX signal propagation
to the target thread.
Move the run/sleep logic to the signal handler and make it adaptive.

BUG=720093
Review-Url: https://codereview.chromium.org/2880493002
Cr-Original-Commit-Position: refs/heads/master@{#470790}
Review-Url: https://codereview.chromium.org/2879313002 .
Cr-Commit-Position: refs/branch-heads/3071@{#556}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/601d38ead4cf9e6e4f28be94a938ea930b61aa62

[alph, 2017-05-15 17:26:24]

Description was changed from

==========
DevTools: More precise CPU throttling rate on Linux

There seems to be some delay during POSIX signal propagation
to the target thread.
Move the run/sleep logic to the signal handler and make it adaptive.

BUG=720093

Review-Url: https://codereview.chromium.org/2880493002
Cr-Commit-Position: refs/heads/master@{#470790}
(cherry picked from commit df33f5f39300a46b43eefb4f8940fac99b37b491)
==========

to

==========
DevTools: More precise CPU throttling rate on Linux

There seems to be some delay during POSIX signal propagation
to the target thread.
Move the run/sleep logic to the signal handler and make it adaptive.

BUG=720093

Review-Url: https://codereview.chromium.org/2880493002
Cr-Original-Commit-Position: refs/heads/master@{#470790}
Review-Url: https://codereview.chromium.org/2879313002 .
Cr-Commit-Position: refs/branch-heads/3071@{#556}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/601d38ead4cf9e6e4f28be94a938...
==========

[alph, 2017-05-15 17:26:25]

Committed patchset #1 (id:1) manually as
601d38ead4cf9e6e4f28be94a938ea930b61aa62.