[Not ready for review] Add Streams API support to FileReader

public/platform/WebBlobRegistry.h

Index: public/platform/WebBlobRegistry.h
diff --git a/public/platform/WebBlobRegistry.h b/public/platform/WebBlobRegistry.h
index 22fa85eaf9c986ae7662c9b08af816d83d220764..59f94f6852d224ef47cf2d8a457cac2438be358b 100644
--- a/public/platform/WebBlobRegistry.h
+++ b/public/platform/WebBlobRegistry.h
@@ -51,7 +51,7 @@ public:
 
     // Registers a stream URL referring to a stream with the specified media
     // type.
-    virtual void registerStreamURL(const WebURL&, const WebString&) { WEBKIT_ASSERT_NOT_REACHED(); }
+    virtual void registerStreamURL(const WebURL&, const WebString&) = 0;
 
     // Registers a blob or stream URL referring to the blob data or stream
     // identified by the specified srcURL.
@@ -61,10 +61,10 @@ public:
     virtual void registerBlobURL(const WebURL&, const WebURL& srcURL) = 0;
 
     // Add data to the stream referred by the URL.
-    virtual void addDataToStream(const WebURL&, WebThreadSafeData&) { WEBKIT_ASSERT_NOT_REACHED(); }
+    virtual void addDataToStream(const WebURL&, WebThreadSafeData&) = 0;
 
     // Tell the registry that this stream won't receive any more data.
-    virtual void finalizeStream(const WebURL&) { WEBKIT_ASSERT_NOT_REACHED(); }
+    virtual void finalizeStream(const WebURL&) = 0;
 
     // Unregisters a blob or stream referred by the URL.
     //