Permissions: Avoid poking at the heap after Blink shutdown

third_party/WebKit/Source/modules/permissions/Permissions.cpp

 // Copyright 2014 The Chromium 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 "modules/permissions/Permissions.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "bindings/core/v8/Nullable.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
@@ skipping 246 matching lines @@
 
 PermissionService* Permissions::getService(ExecutionContext* executionContext) {
   if (!m_service &&
       connectToPermissionService(executionContext, mojo::GetProxy(&m_service)))
     m_service.set_connection_error_handler(convertToBaseCallback(WTF::bind(
         &Permissions::serviceConnectionError, wrapWeakPersistent(this))));
   return m_service.get();
 }
 
 void Permissions::serviceConnectionError() {
+  if (!Platform::current()) {
+    // TODO(rockot): Remove this hack once renderer shutdown sequence is fixed.
+    // Note that reaching this code indicates that the MessageLoop has already
+    // been torn down, so it's impossible for any pending reply callbacks on
+    // |m_service| to fire beyond this point anyway.
+    return;
+  }
   m_service.reset();
 }
 
 void Permissions::taskComplete(ScriptPromiseResolver* resolver,
                                mojom::blink::PermissionDescriptorPtr descriptor,
                                mojom::blink::PermissionStatus result) {
   if (!resolver->getExecutionContext() ||
       resolver->getExecutionContext()->activeDOMObjectsAreStopped())
     return;
   resolver->resolve(
@@ skipping 16 matching lines @@
   result.reserveInitialCapacity(callerIndexToInternalIndex.size());
   for (int internalIndex : callerIndexToInternalIndex) {
     result.append(PermissionStatus::createAndListen(
         resolver->getExecutionContext(), results[internalIndex],
         descriptors[internalIndex]->Clone()));
   }
   resolver->resolve(result);
 }
 
 }  // namespace blink