Only enable the Dart timeline for benchmarks

Only enable the Dart timeline for benchmarks

- Print the event's map if we encounter an error in benchmark_app.
- Add --dart-timeline flag to Dart content handler.
- s/--complete-timeline/--dart-timeline.

Sometimes we were generating a gigabyte of JSON text resulting in a timeout. This should fix that.

R=zra@google.com

Committed: https://chromium.googlesource.com/external/mojo/+/d8a0f5964b1a7c522f14f2a3a1117d3ef47824bd

[Cutch, 2016-02-03 22:22:00]

Description was changed from

==========
Only enable the Dart timeline for benchmarks

BUG=
==========

to

==========
Only enable the Dart timeline for benchmarks

- Print the event's map if we encounter an error in benchmark_app.
- Add --dart-timeline flag to Dart content handler.
- s/--complete-timeline/--dart-timeline.

Sometimes we were generating a gigabyte of JSON text resulting in a timeout.
This should fix that.
==========

[Cutch, 2016-02-03 22:22:01]

johnmccutchan@google.com changed reviewers:
+ zra@google.com

[zra, 2016-02-04 03:39:46]

lgtm with suggestion to make flag names consistent.

https://codereview.chromium.org/1665823003/diff/1/mojo/dart/embedder/dart_con...
File mojo/dart/embedder/dart_controller.h (right):

https://codereview.chromium.org/1665823003/diff/1/mojo/dart/embedder/dart_con...
mojo/dart/embedder/dart_controller.h:103: bool enable_dart_timeline,
dart_timeline_enabled, or change observatory_enabled to enable_observatory.

[Cutch, 2016-02-04 22:13:23]

https://codereview.chromium.org/1665823003/diff/1/mojo/dart/embedder/dart_con...
File mojo/dart/embedder/dart_controller.h (right):

https://codereview.chromium.org/1665823003/diff/1/mojo/dart/embedder/dart_con...
mojo/dart/embedder/dart_controller.h:103: bool enable_dart_timeline,
On 2016/02/04 03:39:46, zra wrote:
> dart_timeline_enabled, or change observatory_enabled to enable_observatory.

Done.

[Cutch, 2016-02-04 22:13:30]

Description was changed from

==========
Only enable the Dart timeline for benchmarks

- Print the event's map if we encounter an error in benchmark_app.
- Add --dart-timeline flag to Dart content handler.
- s/--complete-timeline/--dart-timeline.

Sometimes we were generating a gigabyte of JSON text resulting in a timeout.
This should fix that.
==========

to

==========
Only enable the Dart timeline for benchmarks

- Print the event's map if we encounter an error in benchmark_app.
- Add --dart-timeline flag to Dart content handler.
- s/--complete-timeline/--dart-timeline.

Sometimes we were generating a gigabyte of JSON text resulting in a timeout.
This should fix that.

R=zra@google.com

Committed:
https://chromium.googlesource.com/external/mojo/+/d8a0f5964b1a7c522f14f2a3a11...
==========

[Cutch, 2016-02-04 22:13:31]

Committed patchset #2 (id:20001) manually as
d8a0f5964b1a7c522f14f2a3a1117d3ef47824bd (presubmit successful).