import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1167651 - Passed the forceEnabled pref from function to function down to GLLibraryEGL::EnsureInitialized. r=jgilbert (e0b72d59f)
- Bug 1158120 - Replace gfxIntSize by mozilla::gfx::IntSize in gfx/layers. r=nical (81540669f)
- missing bit Bug 1150767 - Add pref for requiring hardware-backed GL. - r=jrmuizel (0990a4b4b)
- Bug 1150944 - Add a flags parameter to GLContextProvider functions instead of a bool. r=jgilbert (d7a7ade6d)

gfx/layers/basic/BasicLayerManager.cpp

@@ -773,8 +773,8 @@ Transform3D(RefPtr<SourceSurface> aSource,
 
   // Create a surface the size of the transformed object.
   nsRefPtr<gfxASurface> dest = aDest->CurrentSurface();
-  nsRefPtr<gfxImageSurface> destImage = new gfxImageSurface(gfxIntSize(aDestRect.width,
-                                                                       aDestRect.height),
+  nsRefPtr<gfxImageSurface> destImage = new gfxImageSurface(IntSize(aDestRect.width,
+                                                                    aDestRect.height),
                                                             gfxImageFormat::ARGB32);
   gfxPoint offset = aDestRect.TopLeft();