Bug 968148 - Implement PointerCapture for pointer events. r=smaug

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extra : rebase_source : 331cf187194c8827e4b75835e85b2d79fdc419c7
Bug 968148 - Implement PointerCapture for pointer events. tests. r=smaug

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rename : layout/base/tests/test_bug582771.html => layout/base/tests/bug968148_inner.html
rename : dom/indexedDB/test/test_event_propagation.html => layout/base/tests/test_bug968148.html
extra : rebase_source : 723612a9487b7310daf56bfd0120f5ee971fe34e