Merge m-c to inbound

content/canvas/src/WebGLContext.cpp

@@ -437,6 +437,11 @@ WebGLContext::SetContextOptions(JSContext* aCx, JS::Handle<JS::Value> aOptions)
     // enforce that if stencil is specified, we also give back depth
     newOpts.depth |= newOpts.stencil;
 
+    // Don't do antialiasing if we've disabled MSAA.
+    if (!gfxPrefs::MSAALevel()) {
+      newOpts.antialias = false;
+    }
+
 #if 0
     GenerateWarning("aaHint: %d stencil: %d depth: %d alpha: %d premult: %d preserve: %d\n",
                newOpts.antialias ? 1 : 0,

modules/libpref/src/init/all.js

@@ -3701,7 +3701,12 @@ pref("canvas.image.cache.limit", 0);
 pref("image.onload.decode.limit", 0);
 
 // WebGL prefs
+#ifdef ANDROID
+// Disable MSAA on mobile.
+pref("gl.msaa-level", 0);
+#else
 pref("gl.msaa-level", 2);
+#endif
 pref("webgl.force-enabled", false);
 pref("webgl.disabled", false);
 pref("webgl.shader_validator", true);