Add buffering to MimeSniffingResourceHandler.

content/browser/loader/mime_sniffing_resource_handler.h

Index: content/browser/loader/mime_sniffing_resource_handler.h
diff --git a/content/browser/loader/mime_sniffing_resource_handler.h b/content/browser/loader/mime_sniffing_resource_handler.h
index 21200938cb7bb5e76a8fb4c2832d8696d3c05cf9..017cd891d4d032e9600457cdbe5023c593f12ad3 100644
--- a/content/browser/loader/mime_sniffing_resource_handler.h
+++ b/content/browser/loader/mime_sniffing_resource_handler.h
@@ -66,11 +66,6 @@ class CONTENT_EXPORT MimeSniffingResourceHandler
     // about request interception.
     STATE_BUFFERING,
 
-    // In these states, the MimeSniffingResourceHandler is calling OnWillRead on
-    // the downstream ResourceHandler and then waiting for the response.
-    STATE_CALLING_ON_WILL_READ,
-    STATE_WAITING_FOR_BUFFER,
-
     // In this state, the MimeSniffingResourceHandler has identified the mime
     // type and made a decision on whether the request should be intercepted or
     // not. It is nows attempting to replay the response to downstream
@@ -78,9 +73,17 @@ class CONTENT_EXPORT MimeSniffingResourceHandler
     STATE_INTERCEPTION_CHECK_DONE,
 
     // In this state, the MimeSniffingResourceHandler is replaying the buffered
-    // OnResponseStarted event to the downstream ResourceHandlers.
+    // OnResponseStarted event to the downstream ResourceHandlers.  This state
+    // will transition to the next state if there is more data to replay, or
+    // to STATE_STREAMING when replay is done.
     STATE_REPLAYING_RESPONSE_RECEIVED,
 
+    // In this state, the MimeSniffingResourceHandler is replaying the buffered
+    // OnResponseStarted event to the downstream ResourceHandlers, and is
+    // waiting for a buffer from those handlers.  This state always
+    // transitions to the previous one.
+    STATE_REPLAYING_WAIT_FOR_WILL_READ,
+
     // In this state, the MimeSniffingResourceHandler is just a blind
     // pass-through
     // ResourceHandler.
@@ -116,15 +119,12 @@ class CONTENT_EXPORT MimeSniffingResourceHandler
   // Intercepts the request as a stream/download if needed.
   void MaybeIntercept();
 
-  // Calls OnWillRead on the downstream handlers.
-  void CallOnWillRead();
-
-  // Copies received buffer to parent.
-  void BufferReceived();
-
   // Replays OnResponseStarted on the downstream handlers.
   void ReplayResponseReceived();
 
+  // Gets a buffer for read completion.
+  void ReplayGetBuffer();
+
   // Replays OnReadCompleted on the downstreams handlers.
   void ReplayReadCompleted();
 
@@ -178,11 +178,11 @@ class CONTENT_EXPORT MimeSniffingResourceHandler
   scoped_refptr<net::IOBuffer> read_buffer_;
   int read_buffer_size_;
   int bytes_read_;
+  int bytes_replayed_;
 
-  // Pointers to parent-owned read buffer and its size.  Only used for first
-  // OnWillRead call.
-  scoped_refptr<net::IOBuffer>* parent_read_buffer_;
-  int* parent_read_buffer_size_;
+  // Downstream buffer information for replay.
+  scoped_refptr<net::IOBuffer> out_buffer_;
+  int out_buffer_size_;
 
   // The InterceptingResourceHandler that will perform ResourceHandler swap if
   // needed.