Add PARSING_MEDIA_SEGMENT layout test for SourceBuffer mode

Add PARSING_MEDIA_SEGMENT layout test for SourceBuffer mode

Adds layout test to verify that attempt to set
SourceBuffer's append mode fails when enough data has been
appended for the buffer to be in the middle of parsing a
media segment.
Also, removes default WebSourceBuffer::setMode()
implementation now that Chromium WSBI::setMode() has landed.

R=acolwell@chromium.org,jamesr@chromium.org
BUG=249422
TEST=All mediasource layout tests pass locally on Linux

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=165100

[wolenetz, 2014-01-13 21:52:35]

Please take a look:
jamesr: public/platform/* OWNERS review
acolwell: everything

Note: Prerequisite Chromium CL is in CQ still @
https://codereview.chromium.org/134883002/

Thanks!

[jamesr, 2014-01-13 21:53:15]

public/ lgtm

[acolwell GONE FROM CHROMIUM, 2014-01-14 18:20:27]

lgtm % nits

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
File
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html
(right):

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:86:
var truncateAt = Math.floor(segmentInfo.media[0].size * 0.95);  // e.g. first
11238 bytes of 11830
nit: Change the comment to something like 95% of the segment bytes so that it
can't become stale if we happen to reencode the file or change which test clip
that is used by default.

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:97:
assert_true(sourceBuffer.mode == 'segments');
nit: use assert_equals here and in similar checks below.

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:112:
test.done();
nit: remove since it doesn't appear the test is actually done at this point.

[wolenetz, 2014-01-14 19:30:44]

Thanks! Sending to CQ.

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
File
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html
(right):

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:86:
var truncateAt = Math.floor(segmentInfo.media[0].size * 0.95);  // e.g. first
11238 bytes of 11830
On 2014/01/14 18:20:27, acolwell wrote:
> nit: Change the comment to something like 95% of the segment bytes so that it
> can't become stale if we happen to reencode the file or change which test clip
> that is used by default.

Done.

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:97:
assert_true(sourceBuffer.mode == 'segments');
On 2014/01/14 18:20:27, acolwell wrote:
> nit: use assert_equals here and in similar checks below.

Done.

https://codereview.chromium.org/136523004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-sourcebuffer-mode.html:112:
test.done();
On 2014/01/14 18:20:27, acolwell wrote:
> nit: remove since it doesn't appear the test is actually done at this point.

Oh wow! This was a test debugging item I forgot to remove. Thanks for noticing
this.

[commit-bot: I haz the power, 2014-01-14 19:31:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wolenetz@chromium.org/136523004/80001

[commit-bot: I haz the power, 2014-01-15 00:31:29]

Change committed as 165100