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

base/debug/crash_logging.cc

Index: base/debug/crash_logging.cc
diff --git a/base/debug/crash_logging.cc b/base/debug/crash_logging.cc
index 32b6b05e3967312b729ec4193cb5ef960ad75097..b7b65396410be619039968fe7b41a886431e77e5 100644
--- a/base/debug/crash_logging.cc
+++ b/base/debug/crash_logging.cc
@@ -32,6 +32,8 @@ size_t g_chunk_max_length_ = 0;
 // String used to format chunked key names.
 const char kChunkFormatString[] = "%s-%" PRIuS;
 
+bool g_ignore_unregistered_keys_ = false;
+
 // The functions that are called to actually set the key-value pairs in the
 // crash reportng system.
 SetCrashKeyValueFuncT g_set_key_func_ = NULL;
@@ -56,6 +58,10 @@ void SetCrashKeyValue(const base::StringPiece& key,
 
   const CrashKey* crash_key = LookupCrashKey(key);
 
+  if (g_ignore_unregistered_keys_ && !crash_key) {
+    return;
+  }
+
   DCHECK(crash_key) << "All crash keys must be registered before use "
                     << "(key = " << key << ")";
 
@@ -144,7 +150,16 @@ ScopedCrashKey::~ScopedCrashKey() {
 
 size_t InitCrashKeys(const CrashKey* const keys, size_t count,
                      size_t chunk_max_length) {
+  return InitCrashKeys(keys, count, chunk_max_length,
+                       false /* ignore_unregistered_keys */);
+}
+
+size_t InitCrashKeys(const CrashKey* const keys,
+                     size_t count,
+                     size_t chunk_max_length,
+                     bool ignore_unregistered_keys) {
   DCHECK(!g_crash_keys_) << "Crash logging may only be initialized once";
+  g_ignore_unregistered_keys_ = ignore_unregistered_keys;
   if (!keys) {
     delete g_crash_keys_;
     g_crash_keys_ = NULL;
@@ -201,6 +216,7 @@ void ResetCrashLoggingForTesting() {
   g_chunk_max_length_ = 0;
   g_set_key_func_ = NULL;
   g_clear_key_func_ = NULL;
+  g_ignore_unregistered_keys_ = false;
 }
 
 }  // namespace debug