[Qt] Fix a crash in QtPixmapRuntime.

https://bugs.webkit.org/show_bug.cgi?id=117193
Reviewed by Allan Sandfeld Jensen.

The crash could only be reproduced in release builds on Windows.
JSClassCreate calculates the size of JSClassDefinition.staticValues
and staticFunctions by iterating until an entry with a null name is found.

* bridge/qt/qt_pixmapruntime.cpp:
(JSC::Bindings::QtPixmapRuntime::getClassRef):

Task-number: QTBUG-30736
Change-Id: I443c69fd6772b78edbdadb6270c30229b30d992d
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@151170 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>
Make PNGImageDecoder::rowAvailable auto-vectorizable

https://bugs.webkit.org/show_bug.cgi?id=116151

Reviewed by Benjamin Poulain.

Changed the main loops under PNGImageDecoder::rowAvailable so that they
avoid branches and non-sequential table look ups.

Together with automatic vectorization by the compiler this provides around
4x speed-up with AVX or 2x speed-up on generic x64. Shaving off 12-40% on
PNG decoding in general.

* platform/graphics/Color.cpp:
(WebCore::premultipliedARGBFromColor):
* platform/graphics/Color.h:
(WebCore::fastDivideBy255):
* platform/graphics/filters/FEBlend.cpp:
* platform/image-decoders/png/PNGImageDecoder.cpp:
(WebCore::setPixelRGB):
(WebCore::setPixelRGBA):
(WebCore::setPixelRGBA_Premultiplied):
(WebCore::PNGImageDecoder::rowAvailable):

Change-Id: Ic3d6cefda505ebceb37165d0a7aeb3cd2fe3e2c9
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150252 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>
Crash when loading link to audio file

https://bugs.webkit.org/show_bug.cgi?id=115794

Reviewed by Jocelyn Turcotte.

Do not access a null pointer frame.

* loader/appcache/ApplicationCacheHost.cpp:
(WebCore::ApplicationCacheHost::isApplicationCacheEnabled):

Change-Id: I1c7c8ea84394f669e565634f71720ae504ceded4
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149733 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>