ios: Patch cancelAnimationFrame whenever fakeRequestAnimationFrame is used

[tjgrathwell]

The existing implementation of fakeRequestAnimationFrame
did not return a timer ID, so the frame could not be cancelled
if you wanted to cancel it. But if you do want to cancel it,
it needs to be cancelled through clearTimeout instead of
cancelAnimationFrame, because the timer IDs are different.

ex, without the patch this wouldn't work in iOS:

var frameId = requestAnimationFrame(function() { console.log("called"); });
// do some work
if(!stillNeedsToAnimate) { cancelAnimationFrame(frameId); }

[yurydelendik]

/botio test

[pdfjsbot]

From: Bot.io (Windows)

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Received

Command cmd_test from @yurydelendik received. Current queue size: 1

Live output at: http://54.215.176.217:8877/6658f26013393a5/output.txt

[pdfjsbot]

From: Bot.io (Linux)

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Received

Command cmd_test from @yurydelendik received. Current queue size: 1

Live output at: http://107.21.233.14:8877/aca0daee0aeccaa/output.txt

[yurydelendik]

lgtm

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://54.215.176.217:8877/6658f26013393a5/output.txt

Total script time: 23.25 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[pdfjsbot]

From: Bot.io (Linux)

---

Success

Full output at http://107.21.233.14:8877/aca0daee0aeccaa/output.txt

Total script time: 29.21 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[yurydelendik]

Thank you for the patch.