webkit: Fix build in ISO C++ 11 mode

Change-Id: I32b3121ae46678f847dcd74ea74484aaf8f34eaf
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>

Conflicts:
	Source/WebCore/platform/graphics/android/rendering/SurfaceBacking.h