With the recent change to the ExternalTabContainer to have it subclass Widget...

chrome/common/chrome_constants.cc

 // Copyright (c) 2006-2008 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/common/chrome_constants.h"
 
 #include "base/file_path.h"
 
 #define FPL FILE_PATH_LITERAL
 
@@ skipping 25 matching lines @@
     L"Chromium.app/Contents/MacOS/Chromium";
 #endif  // GOOGLE_CHROME_BUILD
 #endif  // OS_*
 #if defined(GOOGLE_CHROME_BUILD)
 const wchar_t kBrowserAppName[] = L"Chrome";
 const char    kStatsFilename[] = "ChromeStats2";
 #else
 const wchar_t kBrowserAppName[] = L"Chromium";
 const char    kStatsFilename[] = "ChromiumStats2";
 #endif
-const wchar_t kExternalTabWindowClass[] = L"Chrome_ExternalTabContainer";
 const wchar_t kMessageWindowClass[] = L"Chrome_MessageWindow";
 const wchar_t kCrashReportLog[] = L"Reported Crashes.txt";
 const wchar_t kTestingInterfaceDLL[] = L"testing_interface.dll";
 const wchar_t kNotSignedInProfile[] = L"Default";
 const wchar_t kNotSignedInID[] = L"not-signed-in";
 const wchar_t kBrowserResourcesDll[] = L"chrome.dll";
 const FilePath::CharType kExtensionFileExtension[] = FPL("crx");
 
 // filenames
 const FilePath::CharType kArchivedHistoryFilename[] = FPL("Archived History");
@@ skipping 30 matching lines @@
 // potentially be tricked into running a product in record mode without
 // knowing it.  Enable in debug builds.  Playback mode is allowed always,
 // because it is useful for testing and not hazardous by itself.
 #ifndef NDEBUG
 const bool kRecordModeEnabled = true;
 #else
 const bool kRecordModeEnabled = false;
 #endif
 
 }  // namespace chrome