Partially componentize chrome/common/crash_keys.

ios/chrome/browser/crash_report/crash_keys.h

Index: ios/chrome/browser/crash_report/crash_keys.h
diff --git a/ios/chrome/browser/crash_report/crash_keys.h b/ios/chrome/browser/crash_report/crash_keys.h
new file mode 100644
index 0000000000000000000000000000000000000000..c0c9bcaa9b3421f0cca1867d4e44faf1a0c1a6f7
--- /dev/null
+++ b/ios/chrome/browser/crash_report/crash_keys.h
@@ -0,0 +1,14 @@
+// Copyright 2015 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 IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_KEYS_H_
+#define IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_KEYS_H_
+
+#include <stddef.h>
+
+// Registers all of the potential crash keys that can be sent to the crash
+// reporting server. Returns the size of the union of all keys.
+size_t RegisterChromeIOSCrashKeys();
+
+#endif  // IOS_CHROME_BROWSER_CRASH_REPORT_CRASH_KEYS_H_