webkit: Fix for memory corruption in computing css value of MediaQuery

RenderStyle object is not owned in MediaQueryEvaluator,
which is latter used in CSSPrimitiveValue::computeLengthFloat.
RenderStyle object is released as it goes out of scope and a memory
corruption is noticed. This patch ensures RenderStyle object
is owned in MediaQueryEvaluator.

Change-Id: I6bceb76d096c950f81bee039b92fa241c66f0a49
CRs-Fixed: 488574
Merge "webkit: Fix for memory corruption in computing css value of MediaQuery"
Revert "Webkit: Utilize LTO (cfxe)"

This reverts commit fb0beee8c5961454c83bfc34add98c6177a9a7ce.
Merge branch 'jb_2.5' of git://codeaurora.org/platform/external/webkit into jb-mv