Bug 1395327 - Disable webrender samplers, as they're causing MacOS to crash. r=kats

MozReview-Commit-ID: EU599EOaZZ7

--HG--
extra : rebase_source : 6e4109b5da8fac62cb71b42239154bcc039299c4

gfx/webrender/src/device.rs

@@ -569,19 +569,23 @@ impl<T> GpuFrameProfile<T> {
     }
 
     fn done_sampler(&mut self) {
+        /* FIXME: samplers crash on MacOS
         debug_assert!(self.inside_frame);
         if self.samplers.pending != 0 {
             self.gl.end_query(gl::SAMPLES_PASSED);
             self.samplers.pending = 0;
         }
+        */
     }
 
-    fn add_sampler(&mut self, tag: T) where T: NamedTag {
+    fn add_sampler(&mut self, _tag: T) where T: NamedTag {
+        /* FIXME: samplers crash on MacOS
         self.done_sampler();
 
         if let Some(query) = self.samplers.add(GpuSampler { tag, count: 0 }) {
             self.gl.begin_query(gl::SAMPLES_PASSED, query);
         }
+        */
     }
 
     fn is_valid(&self) -> bool {