ewk_settings_memory_cache_clear should clear JS garbage and release FastMalloc's free pages to OS
https://bugs.webkit.org/show_bug.cgi?id=112536

Patch by Jose Lejin PJ <jose.lejin@gmail.com> on 2013-03-20
Reviewed by Gyuyoung Kim.

Added changes to clear JS garbage and release FastMalloc's free pages to OS
while calling ewk_settings_memory_cache_clear API.

* ewk/ewk_settings.cpp:
(ewk_settings_memory_cache_clear):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146322 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[Qt] Unreviewed rebaselining after r146206.

The webgl-composite-modes test started failing due to
the newly introduced more restrictive pixel tolerance.
It turns out that the expectation was created without multisampling
enabled. However, Qt does implement this.

* platform/qt/fast/canvas/webgl/webgl-composite-modes-expected.png: Added.
* platform/qt/fast/canvas/webgl/webgl-composite-modes-expected.txt: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146323 268f45cc-cd09-0410-ab3c-d52691b4dbfc