Create CoreTabHelper, move remaining core TCW functionality into it.

chrome/browser/ui/pdf/pdf_tab_observer.h

Index: chrome/browser/ui/pdf/pdf_tab_observer.h
diff --git a/chrome/browser/ui/pdf/pdf_tab_observer.h b/chrome/browser/ui/pdf/pdf_tab_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..0ee2012db43b1abbc2ae88c82416eaf282ee27f1
--- /dev/null
+++ b/chrome/browser/ui/pdf/pdf_tab_observer.h
@@ -0,0 +1,34 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_PDF_PDF_TAB_OBSERVER_H_
+#define CHROME_BROWSER_UI_PDF_PDF_TAB_OBSERVER_H_
+#pragma once
+
+#include "content/browser/tab_contents/tab_contents_observer.h"
+
+class TabContentsWrapper;
+
+// Per-tab class to handle PDF messages.
+class PDFTabObserver : public TabContentsObserver {
+ public:
+  explicit PDFTabObserver(TabContentsWrapper* wrapper);
+  virtual ~PDFTabObserver();
+
+ private:
+  // TabContentsObserver overrides:
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  // Internal helpers ----------------------------------------------------------
+
+  // Message handlers.
+  void OnPDFHasUnsupportedFeature();
+
+  // Our owning TabContentsWrapper.
+  TabContentsWrapper* wrapper_;
+
+  DISALLOW_COPY_AND_ASSIGN(PDFTabObserver);
+};
+
+#endif  // CHROME_BROWSER_UI_PDF_PDF_TAB_OBSERVER_H_