import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

gfx/cairo/quartz-is-clear.patch

@@ -0,0 +1,28 @@
+commit df2b22c8c6677d531194579c82a55e855adff706
+Author: Jeff Muizelaar <jmuizelaar@mozilla.com>
+Date:   Thu Apr 8 15:43:41 2010 -0400
+
+    Propagate is_clear flag to quartz_image_surface
+
+diff --git a/src/cairo-quartz-image-surface.c b/src/cairo-quartz-image-surface.c
+index 5a624eb..b8809d5 100644
+--- a/src/cairo-quartz-image-surface.c
++++ b/src/cairo-quartz-image-surface.c
+@@ -146,6 +146,8 @@ _cairo_quartz_image_surface_flush (void *asurface)
+     surface->image = newImage;
+     CGImageRelease (oldImage);
+ 
++    surface->base.is_clear = surface->imageSurface->base.is_clear;
++
+     return CAIRO_STATUS_SUCCESS;
+ }
+ 
+@@ -267,6 +269,8 @@ cairo_quartz_image_surface_create (cairo_surface_t *surface)
+     qisurf->image = image;
+     qisurf->imageSurface = image_surface;
+ 
++    qisurf->base.is_clear = image_surface->base.is_clear;
++
+     return &qisurf->base;
+ }
+