Log to webrtc logging stream from java code.

webrtc/base/logging.h

Index: webrtc/base/logging.h
diff --git a/webrtc/base/logging.h b/webrtc/base/logging.h
index 4840dfe462d9af161f6f5518781faf5996ca5d86..9347c4aaa320d11c161c7fe7d6448186f6df1a62 100644
--- a/webrtc/base/logging.h
+++ b/webrtc/base/logging.h
@@ -136,6 +136,12 @@ class LogMessage {
   LogMessage(const char* file, int line, LoggingSeverity sev,
              LogErrorContext err_ctx = ERRCTX_NONE, int err = 0,
              const char* module = NULL);
+
+  LogMessage(const char* file,
+             int line,
+             LoggingSeverity sev,
+             const std::string& tag);
+
   ~LogMessage();
 
   static inline bool Loggable(LoggingSeverity sev) { return (sev >= min_sev_); }
@@ -193,7 +199,9 @@ class LogMessage {
   static void UpdateMinLogSeverity() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // These write out the actual log messages.
-  static void OutputToDebug(const std::string& msg, LoggingSeverity severity_);
+  static void OutputToDebug(const std::string& msg,
+                            LoggingSeverity severity,
+                            const std::string& tag);
 
   // The ostream that buffers the formatted message before output
   std::ostringstream print_stream_;
@@ -201,6 +209,9 @@ class LogMessage {
   // The severity level of this message
   LoggingSeverity severity_;
 
+  // The Android debug output tag.
+  std::string android_tag_;
+
   // String data generated in the constructor, that should be appended to
   // the message before output.
   std::string extra_;
@@ -341,6 +352,10 @@ inline bool LogCheckLevel(LoggingSeverity sev) {
   (errno)
 #endif  // WEBRTC_WIN
 
+#define LOG_TAG(sev, tag) \
+  LOG_SEVERITY_PRECONDITION(sev) \
+    rtc::LogMessage(__FILE__, __LINE__, sev, tag).stream()
+
 #define PLOG(sev, err) \
   LOG_ERR_EX(sev, err)