[Merge to 3071] Use faster, but less information methods to calculate memory dumps on macOS.

[Merge to 3071] Use faster, but less information methods to calculate memory dumps on macOS.

> Switch to use mach_vm_region(TOP_INFO) and mach_vm_region(BASIC_INFO) instead of
> mach_vm_region_recurse(). While the latter provides more information, both on
> submaps and on swapped/clean pages, it's two order of magnitudes slower.
> Attempting to take a memory dump with ~50 renderer renderers my machine unusable
> for over a minute.

BUG=713481
Review-Url: https://codereview.chromium.org/2826123004
Cr-Commit-Position: refs/heads/master@{#466417}
(cherry picked from commit 12531f29074985a71e18f60a2e8ea79b4f24314c)

Review-Url: https://codereview.chromium.org/2840733002 .
Cr-Commit-Position: refs/branch-heads/3071@{#177}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/8f0910deb4cac181efa7976efca1a3811dcbe93d

[erikchen, 2017-04-24 21:06:51]

Description was changed from

==========
[Merge to 3071] Use faster, but less information methods to calculate memory
dumps on macOS.

> Switch to use mach_vm_region(TOP_INFO) and mach_vm_region(BASIC_INFO) instead
of
> mach_vm_region_recurse(). While the latter provides more information, both on
> submaps and on swapped/clean pages, it's two order of magnitudes slower.
> Attempting to take a memory dump with ~50 renderer renderers my machine
unusable
> for over a minute.

BUG=713481

Review-Url: https://codereview.chromium.org/2826123004
Cr-Commit-Position: refs/heads/master@{#466417}
(cherry picked from commit 12531f29074985a71e18f60a2e8ea79b4f24314c)
==========

to

==========
[Merge to 3071] Use faster, but less information methods to calculate memory
dumps on macOS.

> Switch to use mach_vm_region(TOP_INFO) and mach_vm_region(BASIC_INFO) instead
of
> mach_vm_region_recurse(). While the latter provides more information, both on
> submaps and on swapped/clean pages, it's two order of magnitudes slower.
> Attempting to take a memory dump with ~50 renderer renderers my machine
unusable
> for over a minute.

BUG=713481

Review-Url: https://codereview.chromium.org/2826123004
Cr-Commit-Position: refs/heads/master@{#466417}
(cherry picked from commit 12531f29074985a71e18f60a2e8ea79b4f24314c)

Review-Url: https://codereview.chromium.org/2840733002 .
Cr-Commit-Position: refs/branch-heads/3071@{#177}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/8f0910deb4cac181efa7976efca1...
==========

[erikchen, 2017-04-24 21:06:53]

Committed patchset #1 (id:1) manually as
8f0910deb4cac181efa7976efca1a3811dcbe93d.