Add QuicStrCat.

net/quic/core/quic_flow_controller_test.cc

 // Copyright 2014 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/quic/core/quic_flow_controller.h"
 
 #include <memory>
 
 #include "base/format_macros.h"
 #include "base/strings/stringprintf.h"
@@ skipping 66 matching lines @@
 
   // Updating with a smaller offset doesn't change anything.
   EXPECT_FALSE(flow_controller_->UpdateSendWindowOffset(send_window_ / 10));
   EXPECT_EQ(send_window_, flow_controller_->SendWindowSize());
 
   // Try to send more bytes, violating flow control.
   EXPECT_CALL(connection_,
               CloseConnection(QUIC_FLOW_CONTROL_SENT_TOO_MUCH_DATA, _, _));
   EXPECT_QUIC_BUG(
       flow_controller_->AddBytesSent(send_window_ * 10),
-      base::StringPrintf("Trying to send an extra %" PRIu64 " bytes",
-                         send_window_ * 10));
+      QuicStrCat("Trying to send an extra ", send_window_ * 10, " bytes"));
   EXPECT_TRUE(flow_controller_->IsBlocked());
   EXPECT_EQ(0u, flow_controller_->SendWindowSize());
 }
 
 TEST_F(QuicFlowControllerTest, ReceivingBytes) {
   Initialize();
 
   EXPECT_FALSE(flow_controller_->IsBlocked());
   EXPECT_FALSE(flow_controller_->FlowControlViolation());
   EXPECT_EQ(kInitialSessionFlowControlWindowForTest,
@@ skipping 268 matching lines @@
   EXPECT_FALSE(flow_controller_->FlowControlViolation());
 
   QuicByteCount new_threshold =
       QuicFlowControllerPeer::WindowUpdateThreshold(flow_controller_.get());
 
   EXPECT_EQ(new_threshold, threshold);
 }
 
 }  // namespace test
 }  // namespace net