Bunch of match preview tweaks:

chrome/browser/tab_contents/match_preview_delegate.h

Index: chrome/browser/tab_contents/match_preview_delegate.h
diff --git a/chrome/browser/tab_contents/match_preview_delegate.h b/chrome/browser/tab_contents/match_preview_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..9d12cf8ff6e4687058f2e81e0e6af9d31a38415c
--- /dev/null
+++ b/chrome/browser/tab_contents/match_preview_delegate.h
@@ -0,0 +1,32 @@
+// Copyright (c) 2010 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_TAB_CONTENTS_MATCH_PREVIEW_DELEGATE_H_
+#define CHROME_BROWSER_TAB_CONTENTS_MATCH_PREVIEW_DELEGATE_H_
+#pragma once
+
+#include "base/string16.h"
+
+// MatchPreview's delegate. Normally the Browser implements this.  See
+// MatchPreview for details.
+class MatchPreviewDelegate {
+ public:
+  // Invoked when the preview TabContents should be shown.
+  virtual void ShowMatchPreview() = 0;
+
+  // Invoked when the preview TabContents should be hidden.
+  virtual void HideMatchPreview() = 0;
+
+  // Invoked when the user does something that should result in the preview
+  // TabContents becoming the active TabContents.
+  virtual void CommitMatchPreview() = 0;
+
+  // Invoked when the suggested text is to change to |text|.
+  virtual void SetSuggestedText(const string16& text) = 0;
+
+ protected:
+  virtual ~MatchPreviewDelegate() {}
+};
+
+#endif  // CHROME_BROWSER_TAB_CONTENTS_MATCH_PREVIEW_DELEGATE_H_