Resume() should return if context is already running

third_party/WebKit/Source/modules/webaudio/AudioContext.cpp

 // Copyright 2015 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/webaudio/AudioContext.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
@@ skipping 137 matching lines @@
   if (isContextClosed()) {
     return ScriptPromise::rejectWithDOMException(
         scriptState,
         DOMException::create(InvalidAccessError,
                              "cannot resume a closed AudioContext"));
   }
 
   ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
   ScriptPromise promise = resolver->promise();
 
+  // If we're already running, just resolve; nothing else needs to be
+  // done.
+  if (contextState() == Running) {
+    resolver->resolve();
+    return promise;
+  }
   // Restart the destination node to pull on the audio graph.
   if (destination()) {
     maybeUnlockUserGesture();
     if (isAllowedToStart()) {
       // Do not set the state to running here.  We wait for the
       // destination to start to set the state.
       startRendering();
     }
   }
 
@@ skipping 86 matching lines @@
     setContextState(Suspended);
     deferredTaskHandler().clearHandlersToBeDeleted();
   }
 }
 
 double AudioContext::baseLatency() const {
   return framesPerBuffer() * 2 / static_cast<double>(sampleRate());
 }
 
 }  // namespace blink