support multiple log message handlers in base/logging.h

components/crash/content/app/breakpad_mac.mm

Index: components/crash/content/app/breakpad_mac.mm
diff --git a/components/crash/content/app/breakpad_mac.mm b/components/crash/content/app/breakpad_mac.mm
index d7ab1ae6389a1a36759d3b637a767d33f13a188d..36d25b204abd955cb19ecac5276c9bfbadd3b509 100644
--- a/components/crash/content/app/breakpad_mac.mm
+++ b/components/crash/content/app/breakpad_mac.mm
@@ -73,8 +73,8 @@ void ClearCrashKeyValueImpl(const base::StringPiece& key) {
   }
 }
 
-bool FatalMessageHandler(int severity, const char* file, int line,
-                         size_t message_start, const std::string& str) {
+bool FatalMessageHandler(int severity,  const std::string&, int line,
+                         const std::string& str) {
   // Do not handle non-FATAL.
   if (severity != logging::LOG_FATAL)
     return false;
@@ -90,16 +90,17 @@ bool FatalMessageHandler(int severity, const char* file, int line,
   base::AutoReset<bool> guard(&guarded, true);
 
   // Only log last path component.  This matches logging.cc.
-  if (file) {
-    const char* slash = strrchr(file, '/');
-    if (slash)
-      file = slash + 1;
-  }
+  size_t last_slash = file.rfind('/');
+  if (last_slash == file.npos)
+    last_slash = 0;
+  else
+    last_slash++;
 
   NSString* fatal_key = @"LOG_FATAL";
   NSString* fatal_value =
       [NSString stringWithFormat:@"%s:%d: %s",
-                                 file, line, str.c_str() + message_start];
+                                 file.substr(last_slash).c_str(), line,
+                                 str.c_str()];
   SetCrashKeyValue(fatal_key, fatal_value);
 
   // Rather than including the code to force the crash here, allow the
@@ -264,7 +265,7 @@ void InitCrashReporter(const std::string& process_type) {
   SetCrashKeyValue(@"prod", [info_dictionary objectForKey:@BREAKPAD_PRODUCT]);
   SetCrashKeyValue(@"plat", @"OS X");
 
-  logging::SetLogMessageHandler(&FatalMessageHandler);
+  logging::AddLogMessageHandler(&FatalMessageHandler);
   base::debug::SetDumpWithoutCrashingFunction(&DumpHelper::DumpWithoutCrashing);
 
   // abort() sends SIGABRT, which breakpad does not intercept.