Bug 929513 - Remove unused #include statements
Bug 929513 - Change gfxSize references to gfx::Size
Bug 929513 - Add YUVUtils class and change gfxIntSize in BasicCompositor

The purpose of this patch is to replace usages of gfxIntSize with
gfx::IntSize in BasicCompositor.

The new class YUVUtils has two methods ported from gfxUtils in thebes.
BasicCompositor now uses these methods instead of the ones in gfxUtils.
Also changed gfxIntSize to gfx::IntSize and gfxImageFormat to
gfx::SurfaceFormat.
Bug 929513 - Replace some instances of gfxIntSize with gfx::IntSize
Bug 929513 - Replace gfxIntSize in layers/AutoOpenSurface.h

This rippled into other replacements in layers and in gfx/gl.