[tracing] child-process-side impl for inter-process memory dumps

[tracing] child-process-side impl for inter-process memory dumps

This CL introduces the implementation for handling the inter-process
memory dumps on the child-process side.
Conceptually this consists of a simple plumbing in TraceMessageFilter
in order to propagate the request up to the browser's MemoryDumpManager,
as the child processes' MDM play a very passive role in the inter-process
coordination game.
In practice, some extra care is required to match the lifetime of MDM
MDM (long) and ChildTraceMessageFilter (shorter) in a thread-safe
manner, which requires the introduction of the proxy class herein
called ChildMemoryDumpManagerDelegateImpl.

More context and design doc are available in the attached BUG.

Reason for NOTRY: all but one bots are green. I started goo.gl/tBX5f1
on infra-dev about the failure and it seems due to a bot out of space.
The change has been sitting for 4+ hours and there are other CLs blocked
on this.

BUG=462930, 474973
NOTRY=true

Committed: https://crrev.com/f2f5ca37b0b57ffcc91abad73b6c81e82e0c2511
Cr-Commit-Position: refs/heads/master@{#324229}

[Primiano Tucci (use gerrit), 2015-03-30 02:51:57]

Patchset #1 (id:1) has been deleted

[nduca, 2015-03-30 20:01:36]

nduca@chromium.org changed reviewers:
+ nduca@chromium.org

[nduca, 2015-03-30 20:01:36]

non-exhaustive owner lgtm. would be good to get someone to second-eye on the
details.

[Primiano Tucci (use gerrit), 2015-03-31 23:30:33]

This is a set of 5 CLs (+ another couple for tests) to implement IPC
synchronization of memory dumps in Chrome.

1) crrev.com/1045613002
2) crrev.com/1042173002
3) crrev.com/1042723002
4) crrev.com/1039963003 [This CL]
5) crrev.com/1039963004

[dsinclair, 2015-04-03 00:31:13]

dsinclair@chromium.org changed reviewers:
+ dsinclair@chromium.org

[dsinclair, 2015-04-03 00:31:14]

lgtm w/ nits.

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
File components/tracing/child_memory_dump_manager_delegate_impl.cc (right):

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
components/tracing/child_memory_dump_manager_delegate_impl.cc:49: // Make sure
we access |ctmf_| only on the thread where it leaves to avoid
nit: did you want leaves, or lives here?

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
File components/tracing/child_memory_dump_manager_delegate_impl.h (right):

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
components/tracing/child_memory_dump_manager_delegate_impl.h:23: // CTMF to the
demands of MDM, which expectes the delegate to be thread-safe
nit: expects

[Primiano Tucci (use gerrit), 2015-04-03 18:00:36]

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
File components/tracing/child_memory_dump_manager_delegate_impl.cc (right):

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
components/tracing/child_memory_dump_manager_delegate_impl.cc:49: // Make sure
we access |ctmf_| only on the thread where it leaves to avoid
On 2015/04/03 00:31:13, dsinclair wrote:
> nit: did you want leaves, or lives here?

Oh lives actually. Good catch ;-)

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
File components/tracing/child_memory_dump_manager_delegate_impl.h (right):

https://codereview.chromium.org/1039963003/diff/60001/components/tracing/chil...
components/tracing/child_memory_dump_manager_delegate_impl.h:23: // CTMF to the
demands of MDM, which expectes the delegate to be thread-safe
On 2015/04/03 00:31:13, dsinclair wrote:
> nit: expects

Done.

[Primiano Tucci (use gerrit), 2015-04-07 07:57:41]

The CQ bit was checked by primiano@chromium.org

[Primiano Tucci (use gerrit), 2015-04-07 07:57:42]

The patchset sent to the CQ was uploaded after l-g-t-m from nduca@chromium.org,
dsinclair@chromium.org
Link to the patchset: https://codereview.chromium.org/1039963003/#ps100001
(title: "Fix tracing_nacl.gyp")

[commit-bot: I haz the power, 2015-04-07 07:57:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039963003/100001

[commit-bot: I haz the power, 2015-04-07 09:04:50]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-07 09:04:51]

Try jobs failed on following builders:
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Primiano Tucci (use gerrit), 2015-04-08 10:52:58]

The CQ bit was checked by primiano@chromium.org

[Primiano Tucci (use gerrit), 2015-04-08 10:52:58]

The patchset sent to the CQ was uploaded after l-g-t-m from
dsinclair@chromium.org, nduca@chromium.org
Link to the patchset: https://codereview.chromium.org/1039963003/#ps120001
(title: "Add temporary workaround for crbug.com/474973")

[commit-bot: I haz the power, 2015-04-08 10:53:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039963003/120001

[Primiano Tucci (use gerrit), 2015-04-08 15:05:51]

The CQ bit was unchecked by primiano@chromium.org

[Primiano Tucci (use gerrit), 2015-04-08 15:09:01]

The CQ bit was checked by primiano@chromium.org

[commit-bot: I haz the power, 2015-04-08 15:09:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1039963003/120001

[commit-bot: I haz the power, 2015-04-08 15:10:50]

Committed patchset #6 (id:120001)

[commit-bot: I haz the power, 2015-04-08 16:05:37]

Patchset 6 (id:??) landed as
https://crrev.com/f2f5ca37b0b57ffcc91abad73b6c81e82e0c2511
Cr-Commit-Position: refs/heads/master@{#324229}