Bug 1413484 - tighten some assertions. r=gerald

mCallback->GetMediaOwner() now is always called before Close() and won't
return null. So is owner->GetMediaElement().

MozReview-Commit-ID: HbxbyuogYAB

--HG--
extra : rebase_source : 28e6ccf104fea9dba9885974f77e19535de84f54
extra : intermediate-source : 15cfa511119ce07e3ede692dc8b14ae177dd388a
extra : source : 9ce161facd920a0efeaf8260ea75f13f1679b24e

dom/media/ChannelMediaResource.cpp

@@ -165,9 +165,10 @@ ChannelMediaResource::OnStartRequest(nsIRequest* aRequest,
   MOZ_DIAGNOSTIC_ASSERT(!mClosed);
 
   MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-  NS_ENSURE_TRUE(owner, NS_ERROR_FAILURE);
+  MOZ_DIAGNOSTIC_ASSERT(owner);
   dom::HTMLMediaElement* element = owner->GetMediaElement();
-  NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);
+  MOZ_DIAGNOSTIC_ASSERT(element);
+
   nsresult status;
   nsresult rv = aRequest->GetStatus(&status);
   NS_ENSURE_SUCCESS(rv, rv);
@@ -522,8 +523,9 @@ ChannelMediaResource::OpenChannel(int64_t aOffset)
 
   // Tell the media element that we are fetching data from a channel.
   MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-  NS_ENSURE_TRUE(owner, NS_ERROR_FAILURE);
+  MOZ_DIAGNOSTIC_ASSERT(owner);
   dom::HTMLMediaElement* element = owner->GetMediaElement();
+  MOZ_DIAGNOSTIC_ASSERT(element);
   element->DownloadResumed();
 
   return NS_OK;
@@ -532,6 +534,7 @@ ChannelMediaResource::OpenChannel(int64_t aOffset)
 nsresult
 ChannelMediaResource::SetupChannelHeaders(int64_t aOffset)
 {
+  MOZ_ASSERT(NS_IsMainThread());
   MOZ_DIAGNOSTIC_ASSERT(!mClosed);
 
   // Always use a byte range request even if we're reading from the start
@@ -548,11 +551,10 @@ ChannelMediaResource::SetupChannelHeaders(int64_t aOffset)
     NS_ENSURE_SUCCESS(rv, rv);
 
     // Send Accept header for video and audio types only (Bug 489071)
-    NS_ASSERTION(NS_IsMainThread(), "Don't call on non-main thread");
     MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-    NS_ENSURE_TRUE(owner, NS_ERROR_FAILURE);
+    MOZ_DIAGNOSTIC_ASSERT(owner);
     dom::HTMLMediaElement* element = owner->GetMediaElement();
-    NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);
+    MOZ_DIAGNOSTIC_ASSERT(element);
     element->SetRequestHeaders(hc);
   } else {
     NS_ASSERTION(aOffset == 0, "Don't know how to seek on this channel type");
@@ -682,15 +684,9 @@ ChannelMediaResource::Suspend(bool aCloseImmediately)
   }
 
   MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-  if (!owner) {
-    // Shutting down; do nothing.
-    return;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(owner);
   dom::HTMLMediaElement* element = owner->GetMediaElement();
-  if (!element) {
-    // Shutting down; do nothing.
-    return;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(element);
 
   if (mChannel && aCloseImmediately && mCacheStream.IsTransportSeekable()) {
     CloseChannel();
@@ -716,15 +712,9 @@ ChannelMediaResource::Resume()
   }
 
   MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-  if (!owner) {
-    // Shutting down; do nothing.
-    return;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(owner);
   dom::HTMLMediaElement* element = owner->GetMediaElement();
-  if (!element) {
-    // Shutting down; do nothing.
-    return;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(element);
 
   if (mSuspendAgent.Resume()) {
     if (mChannel) {
@@ -768,15 +758,10 @@ ChannelMediaResource::RecreateChannel()
     (mLoadInBackground ? nsIRequest::LOAD_BACKGROUND : 0);
 
   MediaDecoderOwner* owner = mCallback->GetMediaOwner();
-  if (!owner) {
-    // The decoder is being shut down, so don't bother opening a new channel
-    return NS_ERROR_ABORT;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(owner);
   dom::HTMLMediaElement* element = owner->GetMediaElement();
-  if (!element) {
-    // The decoder is being shut down, so don't bother opening a new channel
-    return NS_ERROR_ABORT;
-  }
+  MOZ_DIAGNOSTIC_ASSERT(element);
+
   nsCOMPtr<nsILoadGroup> loadGroup = element->GetDocumentLoadGroup();
   NS_ENSURE_TRUE(loadGroup, NS_ERROR_NULL_POINTER);