Add a ConvertableToTraceFormat type to the trace framework.

Add a ConvertableToTraceFormat type to the trace framework.

This patch allows us to have larger objects passed into the trace
framework which, at the point when we output tracing data, will
request they be converted to TraceFormat by calling the
AppendAsTraceFormat method.

BUG=


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193388

[dsinclair, 2013-04-06 21:34:02]

Nat, please take a look.

[nduca, 2013-04-09 22:16:42]

lgtm

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_impl.h
File base/debug/trace_event_impl.h (right):

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:51: class ConvertableToJSON {
So lets call this ConvertableToTraceFormat or something like that that more
clearly states that this is tracing specific, not something that is to be used
for other people using JSON/value types.

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:59: virtual void ToJSON(std::string& out) const =
0;
Should this use the word Append somehow?

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:128: scoped_refptr<base::RefCountedString>
parameter_copy_storage_;
we can remove this in a followup

[dsinclair, 2013-04-09 22:37:45]

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_int...
File base/debug/trace_event_internal.h (right):

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_int...
base/debug/trace_event_internal.h:899: base::debug::ConvertableToJSON* arg,
This has to be scoped_ptr<base::debug::ConvertableToJSON> arg.

[dsinclair, 2013-04-10 01:09:31]

Nat, PTAL.

I fixed it up so you pass in scoped_ptr<ConvertableToTraceFormat> objects. This
has the one downside that I had to make non-templated AddedTraceEvent methods in
trace_event_internal.h with the side effect of, you can't provide other types
with a convertable parameter. So, if you want to use a convertable, and you want
to pass two params, they both have to be convertable.

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_impl.h
File base/debug/trace_event_impl.h (right):

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:51: class ConvertableToJSON {
On 2013/04/09 22:16:42, nduca wrote:
> So lets call this ConvertableToTraceFormat or something like that that more
> clearly states that this is tracing specific, not something that is to be used
> for other people using JSON/value types.

Done.

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:59: virtual void ToJSON(std::string& out) const =
0;
On 2013/04/09 22:16:42, nduca wrote:
> Should this use the word Append somehow?

Done.

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_imp...
base/debug/trace_event_impl.h:128: scoped_refptr<base::RefCountedString>
parameter_copy_storage_;
On 2013/04/09 22:16:42, nduca wrote:
> we can remove this in a followup

Ack.

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_int...
File base/debug/trace_event_internal.h (right):

https://codereview.chromium.org/13590005/diff/7001/base/debug/trace_event_int...
base/debug/trace_event_internal.h:899: base::debug::ConvertableToJSON* arg,
On 2013/04/09 22:37:45, dsinclair wrote:
> This has to be scoped_ptr<base::debug::ConvertableToJSON> arg.

Done.

[nduca, 2013-04-10 01:57:41]

That sounds fine by me. LGTM.

[dsinclair, 2013-04-10 03:20:12]

brettw, can you please take a look for OWNERS approval.

Thanks,
dan

[brettw, 2013-04-10 05:06:56]

lgtm

[commit-bot: I haz the power, 2013-04-10 13:24:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dsinclair@chromium.org/13590005/29001

[commit-bot: I haz the power, 2013-04-10 15:21:50]

Change committed as 193388