Base: Explicitly set abort message on FATAL

Currently bionic only stores the first invocation of
android_set_abort_message, libbase splits the logging invocations
into discrete lines, and liblog automatically calls bionic when
fatal severity is used. This leads to only the first line of
LOG(FATAL) being stored for tombstoned.

Eagerly set the abort message directly before logging when the
severity is FATAL. This ensures the complete message will be
available.

Bug: 120506942
Test: m
Test: manual
Change-Id: I104d6960a2b1f66f21f5ada383fb4ab0f35e96a9

base/logging.cpp

@@ -417,6 +417,14 @@ LogMessage::~LogMessage() {
   }
   std::string msg(data_->ToString());
 
+  if (data_->GetSeverity() == FATAL) {
+#ifdef __ANDROID__
+    // Set the bionic abort message early to avoid liblog doing it
+    // with the individual lines, so that we get the whole message.
+    android_set_abort_message(msg.c_str());
+#endif
+  }
+
   {
     // Do the actual logging with the lock held.
     std::lock_guard<std::mutex> lock(LoggingLock());