Revert of Switch chrome_elf exception handling from breakpad to crashpad.

chrome/common/chrome_constants.h

Index: chrome/common/chrome_constants.h
diff --git a/chrome/common/chrome_constants.h b/chrome/common/chrome_constants.h
index 35ac7cd4850cfe9ef8d5856030f449e480fb7f8d..49c3819e74bcae9e4e58b6b9ef3fffd0868269f4 100644
--- a/chrome/common/chrome_constants.h
+++ b/chrome/common/chrome_constants.h
@@ -32,7 +32,7 @@
 #endif  // OS_MACOSX
 #if defined(OS_WIN)
 extern const base::FilePath::CharType kBrowserResourcesDll[];
-extern const base::FilePath::CharType kChromeElfDllName[];
+extern const base::FilePath::CharType kMetroDriverDll[];
 extern const base::FilePath::CharType kStatusTrayWindowClass[];
 #endif  // defined(OS_WIN)
 
@@ -97,6 +97,13 @@
 extern const int kHighestRendererOomScore;
 #endif
 
+#if defined(OS_WIN)
+// Used by Metro Chrome to initiate navigation and search requests.
+extern const wchar_t kMetroNavigationAndSearchMessage[];
+// Used by Metro Chrome to get information about the current tab.
+extern const wchar_t kMetroGetCurrentTabInfoMessage[];
+#endif
+
 #if defined(OS_CHROMEOS)
 // Chrome OS profile directories have custom prefix.
 // Profile path format: [user_data_dir]/u-[$hash]