Remove unused typemap includes from generated C++ mojo bindings.

content/renderer/presentation/presentation_connection_proxy_unittest.cc

 // Copyright 2017 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 <memory>
 #include <utility>
 
 #include "base/run_loop.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "content/renderer/presentation/presentation_connection_proxy.h"
 #include "content/renderer/presentation/test_presentation_connection.h"
 #include "testing/gmock/include/gmock/gmock.h"
+#include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationConnection.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationController.h"
 
 using ::testing::_;
 
 namespace content {
 
 class PresentationConnectionProxyTest : public ::testing::Test {
  public:
   PresentationConnectionProxyTest() = default;
@@ skipping 82 matching lines @@
 
   controller_connection_proxy_->SendConnectionMessage(
       std::move(session_message),
       base::Bind(
           &PresentationConnectionProxyTest::ExpectSendConnectionMessageCallback,
           base::Unretained(this)));
   run_loop.RunUntilIdle();
 }
 
 }  // namespace content