Support for tracing app initialization.

Support for tracing app initialization.

When compiled in DEBUG mode, or when the "TracingImpl:start" argument
is passed to TracingImpl, collect traces for at least one second. If
the tracing service connects before the time is up, keep the traces;
otherwise, flush and discard them.

Fixes #354

R=qsr@chromium.org, qsr

Committed: https://chromium.googlesource.com/external/mojo/+/8b4e8fe6341de3ee437f0f153466af16e87fbf2c

[etiennej, 2015-09-11 14:18:44]

Per offline discussion, I changed BindingSet to Binding.

[qsr, 2015-09-11 14:44:05]

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/BUILD.gn
File mojo/common/BUILD.gn (right):

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/BUILD.gn#ne...
mojo/common/BUILD.gn:69: ":common",
I think you might not need this anymore, do you?

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/trace_provi...
File mojo/common/trace_provider_impl.cc (right):

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/trace_provi...
mojo/common/trace_provider_impl.cc:48:
base::Bind(&TraceProviderImpl::DelayedStop, base::Unretained(this)));
What is the lifecycle of this object. Are you guaranteed it will still be there
when this comes back (or worst after 1 second?)

[etiennej, 2015-09-11 15:07:32]

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/BUILD.gn
File mojo/common/BUILD.gn (right):

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/BUILD.gn#ne...
mojo/common/BUILD.gn:69: ":common",
On 2015/09/11 14:44:04, qsr wrote:
> I think you might not need this anymore, do you?

Done.

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/trace_provi...
File mojo/common/trace_provider_impl.cc (right):

https://codereview.chromium.org/1334213002/diff/60001/mojo/common/trace_provi...
mojo/common/trace_provider_impl.cc:48:
base::Bind(&TraceProviderImpl::DelayedStop, base::Unretained(this)));
On 2015/09/11 14:44:04, qsr wrote:
> What is the lifecycle of this object. Are you guaranteed it will still be
there
> when this comes back (or worst after 1 second?)

Fixed.

[etiennej, 2015-09-11 15:12:10]

Per offline discussion, simplified the stop dance with weak pointers.

[qsr, 2015-09-11 15:12:21]

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
File mojo/common/tracing_impl.cc (right):

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
mojo/common/tracing_impl.cc:10: #include "base/trace_event/trace_event.h"
Most of those includes seem not useful.

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_impl.h
File mojo/common/tracing_impl.h (right):

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
mojo/common/tracing_impl.h:11: #include "mojo/public/cpp/bindings/binding.h"
This is probably not needed anymore.

https://codereview.chromium.org/1334213002/diff/80001/shell/tracer.h
File shell/tracer.h (right):

https://codereview.chromium.org/1334213002/diff/80001/shell/tracer.h#newcode17
shell/tracer.h:17: #include "mojo/public/cpp/bindings/binding.h"
Not useful.

[etiennej, 2015-09-11 15:15:57]

Patchset #7 (id:110001) has been deleted

[etiennej, 2015-09-11 15:16:45]

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
File mojo/common/tracing_impl.cc (right):

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
mojo/common/tracing_impl.cc:10: #include "base/trace_event/trace_event.h"
On 2015/09/11 15:12:20, qsr wrote:
> Most of those includes seem not useful.

Done.

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_impl.h
File mojo/common/tracing_impl.h (right):

https://codereview.chromium.org/1334213002/diff/80001/mojo/common/tracing_imp...
mojo/common/tracing_impl.h:11: #include "mojo/public/cpp/bindings/binding.h"
On 2015/09/11 15:12:21, qsr wrote:
> This is probably not needed anymore.

Done.

https://codereview.chromium.org/1334213002/diff/80001/shell/tracer.h
File shell/tracer.h (right):

https://codereview.chromium.org/1334213002/diff/80001/shell/tracer.h#newcode17
shell/tracer.h:17: #include "mojo/public/cpp/bindings/binding.h"
On 2015/09/11 15:12:21, qsr wrote:
> Not useful.

Done.

[qsr, 2015-09-11 15:19:47]

lgtm

[etiennej, 2015-09-11 15:21:16]

Committed patchset #7 (id:130001) manually as
8b4e8fe6341de3ee437f0f153466af16e87fbf2c (presubmit successful).