Added OverwriteFlags method to SpdyFrameBuilder.

net/spdy/spdy_frame_builder_test.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/spdy_frame_builder.h"
 
 #include "net/spdy/spdy_framer.h"
 #include "net/spdy/spdy_protocol.h"
 #include "testing/platform_test.h"
 
@@ skipping 41 matching lines @@
   } else {
     builder.WriteFramePrefix(framer, SETTINGS, 0, 0);
   }
   EXPECT_TRUE(builder.GetWritableBuffer(1) != NULL);
   builder.RewriteLength(framer);
   scoped_ptr<SpdyFrame> built(builder.take());
   EXPECT_EQ(base::StringPiece(expected->data(), expected->size()),
             base::StringPiece(built->data(), expected->size()));
 }
 
+TEST_P(SpdyFrameBuilderTest, OverwriteFlags) {
+  // Create a HEADERS frame both via framer and manually via builder with
+  // different flags set, then make them match using OverwriteFlags().
+  SpdyFramer framer(spdy_version_);
+  if (spdy_version_ < SPDY4) {
+    return;
+  }
+  SpdyHeadersIR headers_ir(1);
+  headers_ir.set_end_headers(false);
+  scoped_ptr<SpdyFrame> expected(framer.SerializeHeaders(headers_ir));
+  SpdyFrameBuilder builder(expected->size());
+  builder.WriteFramePrefix(framer, HEADERS, HEADERS_FLAG_END_HEADERS, 1);
+  builder.OverwriteFlags(framer, 0);
+  scoped_ptr<SpdyFrame> built(builder.take());
+  EXPECT_EQ(base::StringPiece(expected->data(), expected->size()),
+            base::StringPiece(built->data(), built->size()));
+}
+
 }  // namespace net