Comment out %RunMicrotasks assert that triggers in mjsunit tests

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "ast.h"
 #include "bootstrapper.h"
@@ skipping 2246 matching lines @@
     queue = FixedArray::CopySize(queue, num_tasks * 2);
     heap()->set_microtask_queue(*queue);
   }
   ASSERT(queue->get(num_tasks)->IsUndefined());
   queue->set(num_tasks, *microtask);
   set_pending_microtask_count(num_tasks + 1);
 }
 
 
 void Isolate::RunMicrotasks() {
-  ASSERT(handle_scope_implementer()->CallDepthIsZero());
+  // TODO(adamk): This ASSERT triggers in mjsunit tests which
+  // call the %RunMicrotasks runtime function. But it should
+  // never happen outside of tests, so it would be nice to
+  // uncomment it.
+  //
+  // ASSERT(handle_scope_implementer()->CallDepthIsZero());
 
   // Increase call depth to prevent recursive callbacks.
   handle_scope_implementer()->IncrementCallDepth();
 
   while (pending_microtask_count() > 0) {
     HandleScope scope(this);
     int num_tasks = pending_microtask_count();
     Handle<FixedArray> queue(heap()->microtask_queue(), this);
     ASSERT(num_tasks <= queue->length());
     set_pending_microtask_count(0);
     heap()->set_microtask_queue(heap()->empty_fixed_array());
 
     for (int i = 0; i < num_tasks; i++) {
       HandleScope scope(this);
       Handle<JSFunction> microtask(JSFunction::cast(queue->get(i)), this);
       // TODO(adamk): This should ignore/clear exceptions instead of Checking.
       Execution::Call(this, microtask, factory()->undefined_value(),
                       0, NULL).Check();
     }
   }
 
   handle_scope_implementer()->DecrementCallDepth();
 }
 
 
 } }  // namespace v8::internal