Die, DemuxerStream::QueryInterface, die!

This appears to have been an attempt at hand-rolling an RTTI system, all for the
use of a *single* class (!).  Removing it makes for cleaner, simpler, shorter
code.  It also enables delegating DemuxerStreams, which wasn't possible before
(b/c the overridable method was protected, so not visible to a HAS-A wrapper).

BUG=none
TEST=trybots

Review URL: http://codereview.chromium.org/6730006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79309 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 6 insertions, 20 deletions

diff --git a/media/base/filters.cc b/media/base/filters.cc
index fc5f537..1386842 100644
--- a/media/base/filters.cc
+++ b/media/base/filters.cc
@@ -66,7 +66,7 @@ void Filter::Seek(base::TimeDelta time, FilterCallback* callback) {
 void Filter::OnAudioRendererDisabled() {
 }
 
-void* DemuxerStream::QueryInterface(const char* interface_id) {
+AVStream* DemuxerStream::GetAVStream() {
   return NULL;
 }
 
diff --git a/media/base/filters.h b/media/base/filters.h
index d6b962d..88e6143 100644
--- a/media/base/filters.h
+++ b/media/base/filters.h
@@ -33,6 +33,8 @@
 #include "media/base/media_format.h"
 #include "media/base/video_frame.h"
 
+struct AVStream;
+
 namespace media {
 
 class Buffer;
@@ -144,16 +146,8 @@ class DemuxerStream : public base::RefCountedThreadSafe<DemuxerStream> {
   // TODO(scherkus): switch Read() callback to scoped_refptr<>.
   virtual void Read(Callback1<Buffer*>::Type* read_callback) = 0;
 
-  // Given a class that supports the |Interface| and a related static method
-  // interface_id(), which returns a const char*, this method returns true if
-  // the class returns an interface pointer and assigns the pointer to
-  // |interface_out|.  Otherwise this method returns false.
-  template <class Interface>
-  bool QueryInterface(Interface** interface_out) {
-    void* i = QueryInterface(Interface::interface_id());
-    *interface_out = reinterpret_cast<Interface*>(i);
-    return (NULL != i);
-  };
+  // Returns an |AVStream*| if supported, or NULL.
+  virtual AVStream* GetAVStream();
 
   // Returns the type of stream.
   virtual Type type() = 0;
@@ -164,14 +158,6 @@ class DemuxerStream : public base::RefCountedThreadSafe<DemuxerStream> {
   virtual void EnableBitstreamConverter() = 0;
 
  protected:
-  // Optional method that is implemented by filters that support extended
-  // interfaces.  The filter should return a pointer to the interface
-  // associated with the |interface_id| string if they support it, otherwise
-  // return NULL to indicate the interface is unknown.  The derived filter
-  // should NOT AddRef() the interface.  The DemuxerStream::QueryInterface()
-  // public template function will assign the interface to a scoped_refptr<>.
-  virtual void* QueryInterface(const char* interface_id);
-
   friend class base::RefCountedThreadSafe<DemuxerStream>;
   virtual ~DemuxerStream();
 };
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index 44d3236..205218f 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -156,7 +156,7 @@ class MockDemuxerStream : public DemuxerStream {
   MOCK_METHOD0(type, Type());
   MOCK_METHOD0(media_format, const MediaFormat&());
   MOCK_METHOD1(Read, void(Callback1<Buffer*>::Type* read_callback));
-  MOCK_METHOD1(QueryInterface, void*(const char* interface_id));
+  MOCK_METHOD0(GetAVStream, AVStream*());
   MOCK_METHOD0(EnableBitstreamConverter, void());
 
  protected: