Either already fixed or we can send upstream. 

--- mozilla-esr31/gfx/2d/DataSurfaceHelpers.cpp.orig	2015-06-04 17:42:52.952071382 -0700
+++ mozilla-esr31/gfx/2d/DataSurfaceHelpers.cpp	2015-06-04 17:42:52.954656062 -0700
@@ -19,11 +19,7 @@
 
   for (int row = 0; row < aSize.height; ++row) {
     for (int column = 0; column < aSize.width; ++column) {
-#ifdef IS_BIG_ENDIAN
-      pixel[column] |= 0x000000FF;
-#else
       pixel[column] |= 0xFF000000;
-#endif
     }
     pixel += (aStride/4);
   }