Define crash keys in the directory hierarchy where they are used.

components/crash/core/common/crash_keys.h

Index: components/crash/core/common/crash_keys.h
diff --git a/components/crash/core/common/crash_keys.h b/components/crash/core/common/crash_keys.h
index fdd1ee53f745296ee36d4e4004c77ac032ba32d1..7da503c4415611b644a7f3846c16c7f9bbedda17 100644
--- a/components/crash/core/common/crash_keys.h
+++ b/components/crash/core/common/crash_keys.h
@@ -19,6 +19,7 @@ class CommandLine;
 
 namespace crash_keys {
 
+
 // Sets the ID (which may either be a full GUID or a GUID that was already
 // stripped from its dashes -- in either case this method will strip remaining
 // dashes before setting the crash key).
@@ -32,6 +33,9 @@ void SetVariationsList(const std::vector<std::string>& variations);
 void GetCrashKeysForCommandLineSwitches(
     std::vector<base::debug::CrashKey>* keys);
 
+// Appends crash keys used under //components/crash to |keys|.
+void AppendCrashCrashKeys(std::vector<base::debug::CrashKey>* keys);
+
 // A function returning true if |flag| is a switch that should be filtered out
 // of crash keys.
 using SwitchFilterFunction = bool (*)(const std::string& flag);