Add possibility to ignore unregistered crash keys. Use this from WebView

base/debug/crash_logging.h

Index: base/debug/crash_logging.h
diff --git a/base/debug/crash_logging.h b/base/debug/crash_logging.h
index eaa65e4cff9959d527f5694e52107737a42fc886..3ce0b41f1f6f417232050d735506813e2e66f796 100644
--- a/base/debug/crash_logging.h
+++ b/base/debug/crash_logging.h
@@ -110,6 +110,13 @@ struct BASE_EXPORT CrashKey {
 // chunk can be.
 BASE_EXPORT size_t InitCrashKeys(const CrashKey* const keys, size_t count,
                                  size_t chunk_max_length);
+// Some clients need to log a sub-set of the crash-keys added by lower layers,
+// |ignore_unregistered_keys| allows clients to ignore any keys that haven't
+// been explicitly registered.
+BASE_EXPORT size_t InitCrashKeys(const CrashKey* const keys,
+                                 size_t count,
+                                 size_t chunk_max_length,
+                                 bool ignore_unregistered_keys);
 
 // Returns the corresponding crash key object or NULL for a given key.
 BASE_EXPORT const CrashKey* LookupCrashKey(const base::StringPiece& key);