Fix a small error in exception handling in convertToBlob

Fix a small error in exception handling in convertToBlob

The spec for convertToBlob is here:
https://html.spec.whatwg.org/multipage/scripting.html#dom-offscreencanvas-converttoblob

There are three cases where this API should throw exception, and we don't
have the test to cover that.

Also, our code does not handle the third case in the above spec.

This CL adds layout tests to cover the exception cases and fix the third
case.

BUG=659260
Committed: https://crrev.com/8e9a7bc6d79b084d3562563d2c2aa06c3390965d
Cr-Commit-Position: refs/heads/master@{#433673}

[xidachen, 2016-11-21 16:09:27]

xidachen@chromium.org changed reviewers:
+ xlai@chromium.org

[xidachen, 2016-11-21 16:09:28]

PTAL

[xlai (Olivia), 2016-11-21 16:34:02]

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp (right):

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:208:
IndexSizeError, "Zero-sized OffscreenCanvas cannot be transferred.");
Also, change the error msg. I think it has nothing to do with "transfer".

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:213: return
ScriptPromise();
Actually, the third case is already handled in this if block
(!this->isPaintable()) but it's just returning an empty promise. Try to throw an
exception here instead of creating a new if block.

[xidachen, 2016-11-21 16:40:28]

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp (right):

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:208:
IndexSizeError, "Zero-sized OffscreenCanvas cannot be transferred.");
On 2016/11/21 16:34:00, xlai (Olivia) wrote:
> Also, change the error msg. I think it has nothing to do with "transfer".

Done.

https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:213: return
ScriptPromise();
On 2016/11/21 16:34:00, xlai (Olivia) wrote:
> Actually, the third case is already handled in this if block
> (!this->isPaintable()) but it's just returning an empty promise. Try to throw
an
> exception here instead of creating a new if block.

Done, makes perfect sense.

[xlai (Olivia), 2016-11-21 19:23:15]

On 2016/11/21 16:40:28, xidachen wrote:
>
https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
> File third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp
(right):
> 
>
https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
> third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:208:
> IndexSizeError, "Zero-sized OffscreenCanvas cannot be transferred.");
> On 2016/11/21 16:34:00, xlai (Olivia) wrote:
> > Also, change the error msg. I think it has nothing to do with "transfer".
> 
> Done.
> 
>
https://codereview.chromium.org/2520973002/diff/1/third_party/WebKit/Source/c...
> third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.cpp:213: return
> ScriptPromise();
> On 2016/11/21 16:34:00, xlai (Olivia) wrote:
> > Actually, the third case is already handled in this if block
> > (!this->isPaintable()) but it's just returning an empty promise. Try to
throw
> an
> > exception here instead of creating a new if block.
> 
> Done, makes perfect sense.

lgtm

[xidachen, 2016-11-21 19:26:38]

The CQ bit was checked by xidachen@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-21 19:27:31]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[xidachen, 2016-11-21 20:51:14]

The CQ bit was unchecked by xidachen@chromium.org

[xidachen, 2016-11-21 20:51:19]

The CQ bit was checked by xidachen@chromium.org

[commit-bot: I haz the power, 2016-11-21 20:52:15]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-21 22:24:47]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1479761479570340,
"parent_rev": "602ccf084ee5904d1ac441af11b1efaf7ce9c131", "commit_rev":
"c16f68248441d80c9b3da6ba7b901352cebdadc8"}

[commit-bot: I haz the power, 2016-11-21 22:25:12]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-11-21 22:29:05]

Description was changed from

==========
Fix a small error in exception handling in convertToBlob

The spec for convertToBlob is here:
https://html.spec.whatwg.org/multipage/scripting.html#dom-offscreencanvas-con...

There are three cases where this API should throw exception, and we don't
have the test to cover that.

Also, our code does not handle the third case in the above spec.

This CL adds layout tests to cover the exception cases and fix the third
case.

BUG=659260
==========

to

==========
Fix a small error in exception handling in convertToBlob

The spec for convertToBlob is here:
https://html.spec.whatwg.org/multipage/scripting.html#dom-offscreencanvas-con...

There are three cases where this API should throw exception, and we don't
have the test to cover that.

Also, our code does not handle the third case in the above spec.

This CL adds layout tests to cover the exception cases and fix the third
case.

BUG=659260

Committed: https://crrev.com/8e9a7bc6d79b084d3562563d2c2aa06c3390965d
Cr-Commit-Position: refs/heads/master@{#433673}
==========

[commit-bot: I haz the power, 2016-11-21 22:29:06]

Patchset 2 (id:??) landed as
https://crrev.com/8e9a7bc6d79b084d3562563d2c2aa06c3390965d
Cr-Commit-Position: refs/heads/master@{#433673}