Don't throw for unparseable frames.

Don't throw for unparseable frames.

If the stack trace parser throws when it encounters a frame it doesn't
understand, that tends to obscure other errors and generally make life
difficult for users.

R=rnystrom@google.com

Committed: https://github.com/dart-lang/stack_trace/commit/a636572cf3f553a1601e6d3c6c82a2c323b40626

[Bob Nystrom, 2015-08-12 16:47:56]

LGTM!

https://codereview.chromium.org/1283113002/diff/1/CHANGELOG.md
File CHANGELOG.md (right):

https://codereview.chromium.org/1283113002/diff/1/CHANGELOG.md#newcode5
CHANGELOG.md:5: `UnparseableFrame`, which exposes no metadata but preserves the
frame's
[UnparsedFrame].

https://codereview.chromium.org/1283113002/diff/1/lib/src/unparsed_frame.dart
File lib/src/unparsed_frame.dart (right):

https://codereview.chromium.org/1283113002/diff/1/lib/src/unparsed_frame.dart...
lib/src/unparsed_frame.dart:15: final int column = null;
Do users expect that these are nullable? It may be safer to return 0 or -1.

[nweiz, 2015-08-12 20:38:20]

Code review changes

[nweiz, 2015-08-12 20:38:42]

https://codereview.chromium.org/1283113002/diff/1/CHANGELOG.md
File CHANGELOG.md (right):

https://codereview.chromium.org/1283113002/diff/1/CHANGELOG.md#newcode5
CHANGELOG.md:5: `UnparseableFrame`, which exposes no metadata but preserves the
frame's
On 2015/08/12 16:47:56, Bob Nystrom wrote:
> [UnparsedFrame].

Done.

https://codereview.chromium.org/1283113002/diff/1/lib/src/unparsed_frame.dart
File lib/src/unparsed_frame.dart (right):

https://codereview.chromium.org/1283113002/diff/1/lib/src/unparsed_frame.dart...
lib/src/unparsed_frame.dart:15: final int column = null;
On 2015/08/12 16:47:56, Bob Nystrom wrote:
> Do users expect that these are nullable? It may be safer to return 0 or -1.

Yes, it's clearly documented in Frame and in practice stack frames don't include
line/column info reasonably often. Also if users are expecting them to be valid,
null will fail faster than a sentinel int.

[nweiz, 2015-08-12 20:38:51]

Committed patchset #2 (id:20001) manually as
a636572cf3f553a1601e6d3c6c82a2c323b40626 (presubmit successful).