Bug 1216308 - Hoist IsCallerChrome check in HTMLMediaElement::Play to API entry point. r=bz

dom/html/HTMLMediaElement.cpp

@@ -2221,13 +2221,22 @@ HTMLMediaElement::ResetConnectionState()
 
 void
 HTMLMediaElement::Play(ErrorResult& aRv)
+{
+  nsresult rv = PlayInternal(nsContentUtils::IsCallerChrome());
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+  }
+}
+
+nsresult
+HTMLMediaElement::PlayInternal(bool aCallerIsChrome)
 {
   // Prevent media element from being auto-started by a script when
   // media.autoplay.enabled=false
   if (!mHasUserInteraction
       && !IsAutoplayEnabled()
       && !EventStateManager::IsHandlingUserInput()
-      && !nsContentUtils::IsCallerChrome()) {
+      && !aCallerIsChrome) {
     LOG(LogLevel::Debug, ("%p Blocked attempt to autoplay media.", this));
 #if defined(MOZ_WIDGET_ANDROID)
     nsContentUtils::DispatchTrustedEvent(OwnerDoc(),
@@ -2236,7 +2245,7 @@ HTMLMediaElement::Play(ErrorResult& aRv)
                                          false,
                                          false);
 #endif
-    return;
+    return NS_OK;
   }
 
   // Play was not blocked so assume user interacted with the element.
@@ -2257,7 +2266,7 @@ HTMLMediaElement::Play(ErrorResult& aRv)
       OwnerDoc()->Hidden()) {
     LOG(LogLevel::Debug, ("%p Blocked playback because owner hidden.", this));
     mPlayBlockedBecauseHidden = true;
-    return;
+    return NS_OK;
   }
 
   // Even if we just did Load() or ResumeLoad(), we could already have a decoder
@@ -2267,9 +2276,9 @@ HTMLMediaElement::Play(ErrorResult& aRv)
       SetCurrentTime(0);
     }
     if (!mPausedForInactiveDocumentOrChannel) {
-      aRv = mDecoder->Play();
-      if (aRv.Failed()) {
-        return;
+      nsresult rv = mDecoder->Play();
+      if (NS_FAILED(rv)) {
+        return rv;
       }
     }
   }
@@ -2305,13 +2314,13 @@ HTMLMediaElement::Play(ErrorResult& aRv)
   AddRemoveSelfReference();
   UpdatePreloadAction();
   UpdateSrcMediaStreamPlaying();
+
+  return NS_OK;
 }
 
 NS_IMETHODIMP HTMLMediaElement::Play()
 {
-  ErrorResult rv;
-  Play(rv);
-  return rv.StealNSResult();
+  return PlayInternal(/* aCallerIsChrome = */ true);
 }
 
 HTMLMediaElement::WakeLockBoolWrapper&