renderer/extensions: Forward declare a couple of v8 classes in EventBindings header.

chrome/renderer/extensions/event_bindings.cc

 // Copyright (c) 2011 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 "chrome/renderer/extensions/event_bindings.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
@@ skipping 13 matching lines @@
 #include "content/renderer/v8_value_converter.h"
 #include "googleurl/src/gurl.h"
 #include "grit/renderer_resources.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDataSource.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebSecurityOrigin.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURL.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURLRequest.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
+#include "v8/include/v8.h"
 
 using bindings_utils::CallFunctionInContext;
 using bindings_utils::ContextInfo;
 using bindings_utils::ContextList;
 using bindings_utils::GetContexts;
 using bindings_utils::GetInfoForCurrentContext;
 using bindings_utils::GetStringResource;
 using bindings_utils::ExtensionBase;
 using bindings_utils::GetPendingRequestMap;
 using bindings_utils::PendingRequestMap;
@@ skipping 378 matching lines @@
     // TODO(rafaelw): Consider only doing this check if function_name ==
     // "Event.dispatchJSON".
 #ifndef NDEBUG
     if (!retval.IsEmpty() && !retval->IsUndefined()) {
       std::string error = *v8::String::AsciiValue(retval);
       DCHECK(false) << error;
     }
 #endif
   }
 }