Correctly propagate end value for exponential ramp

Correctly propagate end value for exponential ramp

When the start and end values of an exponential ramp have opposite
signs, the exponential ramp should propagate the start value.
Previously, it would, until the end of the exponential ramp where the
output would jump to the specified end value of the ramp.

BUG=574529
TEST=audioparam-negative-exponentialRamp.html updated with test.

Committed: https://crrev.com/efe8e531bbf3e7a2fa7ca82fb46d208cad9fe6cf
Cr-Commit-Position: refs/heads/master@{#369228}

[Raymond Toy, 2016-01-06 22:03:38]

rtoy@chromium.org changed reviewers:
+ hongchan@chromium.org

[Raymond Toy, 2016-01-06 22:03:39]

PTAL.

[Raymond Toy, 2016-01-06 22:05:02]

https://codereview.chromium.org/1561483004/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp (left):

https://codereview.chromium.org/1561483004/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/webaudio/AudioParamTimeline.cpp:417: 
I think this is actually incorrect and was just a workaround for exponentialRamp
starting at the correct value when the start and end values have different
signs.

[Raymond Toy, 2016-01-13 17:36:08]

Ping.

[hongchan, 2016-01-13 17:39:25]

lgtm

[Raymond Toy, 2016-01-13 17:43:26]

The CQ bit was checked by rtoy@chromium.org

[commit-bot: I haz the power, 2016-01-13 17:44:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1561483004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1561483004/40001

[commit-bot: I haz the power, 2016-01-13 19:00:16]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-01-13 19:01:03]

Description was changed from

==========
Correctly propagate end value for exponential ramp

When the start and end values of an exponential ramp have opposite
signs, the exponential ramp should propagate the start value.
Previously, it would, until the end of the exponential ramp where the
output would jump to the specified end value of the ramp.

BUG=574529
TEST=audioparam-negative-exponentialRamp.html updated with test.
==========

to

==========
Correctly propagate end value for exponential ramp

When the start and end values of an exponential ramp have opposite
signs, the exponential ramp should propagate the start value.
Previously, it would, until the end of the exponential ramp where the
output would jump to the specified end value of the ramp.

BUG=574529
TEST=audioparam-negative-exponentialRamp.html updated with test.

Committed: https://crrev.com/efe8e531bbf3e7a2fa7ca82fb46d208cad9fe6cf
Cr-Commit-Position: refs/heads/master@{#369228}
==========

[commit-bot: I haz the power, 2016-01-13 19:01:04]

Patchset 3 (id:??) landed as
https://crrev.com/efe8e531bbf3e7a2fa7ca82fb46d208cad9fe6cf
Cr-Commit-Position: refs/heads/master@{#369228}