support multiple log message handlers in base/logging.h

components/crash/content/app/crashpad.cc

Index: components/crash/content/app/crashpad.cc
diff --git a/components/crash/content/app/crashpad.cc b/components/crash/content/app/crashpad.cc
index 76f67348ab0fcb6cd0e7ed3412a410d31be569da..5d9753b5ed4b48bab92ae680617ad43a15dc308e 100644
--- a/components/crash/content/app/crashpad.cc
+++ b/components/crash/content/app/crashpad.cc
@@ -53,9 +53,8 @@ void ClearCrashKey(const base::StringPiece& key) {
 }
 
 bool LogMessageHandler(int severity,
-                       const char* file,
+                       const std::string& file,
                        int line,
-                       size_t message_start,
                        const std::string& string) {
   // Only handle FATAL.
   if (severity != logging::LOG_FATAL) {
@@ -73,16 +72,15 @@ bool LogMessageHandler(int severity,
   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;
-    }
-  }
-
-  CHECK_LE(message_start, string.size());
-  std::string message = base::StringPrintf("%s:%d: %s", file, line,
-                                           string.c_str() + message_start);
+  size_t last_slash = file.rfind('/');
+  if (last_slash == file.npos)
+    last_slash = 0;
+  else
+    last_slash++;
+
+  std::string message = base::StringPrintf("%s:%d: %s",
+                                           file.substr(last_slash).c_str(),
+                                           line, string.c_str());
   SetCrashKeyValue("LOG_FATAL", message);
 
   // Rather than including the code to force the crash here, allow the caller to
@@ -164,7 +162,7 @@ void InitializeCrashpadImpl(bool initial_client,
   SetCrashKeyValue("pid", base::IntToString(::GetCurrentProcessId()));
 #endif
 
-  logging::SetLogMessageHandler(LogMessageHandler);
+  logging::AddLogMessageHandler(LogMessageHandler);
 
   // If clients called CRASHPAD_SIMULATE_CRASH() instead of
   // base::debug::DumpWithoutCrashing(), these dumps would appear as crashes in