Bug 1173463 - Add MediaResource::GetContentURL(). r=cpearce

Remember the content url a MediaResource is loaded from
at ctor time and make it available for debugging purposes.

--HG--
extra : rebase_source : 4768b6a6cb6a6c43f37c8f0132e63acf59ecb80f

dom/media/MediaResource.h

@@ -428,6 +428,8 @@ public:
     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
   }
 
+  const nsCString& GetContentURL() const { return EmptyCString(); }
+
 protected:
   virtual ~MediaResource() {};
 
@@ -460,6 +462,12 @@ public:
     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
   }
 
+  // Returns the url of the resource. Safe to call from any thread?
+  const nsCString& GetContentURL() const
+  {
+    return mContentURL;
+  }
+
 protected:
   BaseMediaResource(MediaDecoder* aDecoder,
                     nsIChannel* aChannel,
@@ -473,6 +481,7 @@ protected:
   {
     MOZ_COUNT_CTOR(BaseMediaResource);
     NS_ASSERTION(!mContentType.IsEmpty(), "Must know content type");
+    mURI->GetSpec(mContentURL);
   }
   virtual ~BaseMediaResource()
   {
@@ -511,6 +520,9 @@ protected:
   // is safe.
   const nsAutoCString mContentType;
 
+  // Copy of the url of the channel resource.
+  nsAutoCString mContentURL;
+
   // True if SetLoadInBackground() has been called with
   // aLoadInBackground = true, i.e. when the document load event is not
   // blocked by this resource, and all channel loads will be in the