Bug 1188150 - Move ContainerParser dtor to implementation. r=jya

This blocks inlining so callers don't have to include
SourceBufferResource.h &c. Intended to simplify unit tests.

dom/media/mediasource/ContainerParser.cpp

@@ -39,6 +39,8 @@ ContainerParser::ContainerParser(const nsACString& aType)
 {
 }
 
+ContainerParser::~ContainerParser() = default;
+
 bool
 ContainerParser::IsInitSegmentPresent(MediaByteBuffer* aData)
 {

dom/media/mediasource/ContainerParser.h

@@ -19,7 +19,7 @@ class SourceBufferResource;
 class ContainerParser {
 public:
   explicit ContainerParser(const nsACString& aType);
-  virtual ~ContainerParser() = default;
+  virtual ~ContainerParser();
 
   // Return true if aData starts with an initialization segment.
   // The base implementation exists only for debug logging and is expected