Allow multiple logging::LogMessage{Handler,Listener}s

ios/chrome/browser/crash_report/breakpad_helper.mm

Index: ios/chrome/browser/crash_report/breakpad_helper.mm
diff --git a/ios/chrome/browser/crash_report/breakpad_helper.mm b/ios/chrome/browser/crash_report/breakpad_helper.mm
index 252df3da7c5b61499a37109909f392706885147d..efd82573eca19241d3e40502ca6b373adb15b263 100644
--- a/ios/chrome/browser/crash_report/breakpad_helper.mm
+++ b/ios/chrome/browser/crash_report/breakpad_helper.mm
@@ -78,15 +78,15 @@ void ClearCrashKeyValueImpl(const base::StringPiece& key) {
   RemoveReportParameter(base::SysUTF8ToNSString(key.as_string()));
 }
 
-// Callback for logging::SetLogMessageHandler
-bool FatalMessageHandler(int severity,
-                         const char* file,
-                         int line,
-                         size_t message_start,
-                         const std::string& str) {
+// Callback for logging::AddLogMessageListener
+void FatalMessageListener(int severity,
+                          const char* file,
+                          int line,
+                          size_t message_start,
+                          const std::string& str) {
   // Do not handle non-FATAL.
   if (severity != logging::LOG_FATAL)
-    return false;
+    return;
 
   // In case of OOM condition, this code could be reentered when
   // constructing and storing the key.  Using a static is not
@@ -94,7 +94,7 @@ bool FatalMessageHandler(int severity,
   // fatal crash at the same time, this should work.
   static bool guarded = false;
   if (guarded)
-    return false;
+    return;
 
   base::AutoReset<bool> guard(&guarded, true);
 
@@ -112,7 +112,6 @@ bool FatalMessageHandler(int severity,
 
   // Rather than including the code to force the crash here, allow the
   // caller to do it.
-  return false;
 }
 
 // Caches the uploading flag in NSUserDefaults, so that we can access the value
@@ -130,7 +129,7 @@ void Start(const std::string& channel_name) {
   [[BreakpadController sharedInstance] start:YES];
   base::debug::SetCrashKeyReportingFunctions(&SetCrashKeyValueImpl,
                                              &ClearCrashKeyValueImpl);
-  logging::SetLogMessageHandler(&FatalMessageHandler);
+  logging::AddLogMessageListener(FatalMessageListener);
   g_crash_reporter_enabled = true;
   // Register channel information.
   if (channel_name.length()) {