logd: refactor LastLogTimes a bit

There's still plenty of work that can be done here, particularly
re-doing the locking so each LogReaderThread does not mutually exclude
the others, but that's out of the scope here.

This change primarily removes the public 'mTimes' from LogBuffer and
creates a new LogReaderList class instead.  It would have merged this
into LogReader, but that creates a circular dependency.

This change also removes the need to reference LogReader or
LogReaderList from LogAudit, LogKLog, and LogListener, instead relying
on LogBuffer()::log() to call LogReaderList::NotifyNewLog().

Test: logging unit tests
Change-Id: Ia874b57a9ec1254af1295bfa6f7af2f92a75755b
diff --git a/logd/LogReader.h b/logd/LogReader.h
index f00cc21..7df3f6b 100644
--- a/logd/LogReader.h
+++ b/logd/LogReader.h
@@ -18,6 +18,7 @@
 
 #include <sysutils/SocketListener.h>
 
+#include "LogReaderList.h"
 #include "LogReaderThread.h"
 
 #define LOGD_SNDTIMEO 32
@@ -25,21 +26,19 @@
 class LogBuffer;
 
 class LogReader : public SocketListener {
-    LogBuffer& mLogbuf;
+  public:
+    explicit LogReader(LogBuffer* logbuf, LogReaderList* reader_list);
 
-   public:
-    explicit LogReader(LogBuffer* logbuf);
-    void notifyNewLog(unsigned int logMask);
+    LogBuffer* log_buffer() const { return log_buffer_; }
 
-    LogBuffer& logbuf(void) const {
-        return mLogbuf;
-    }
-
-   protected:
+  protected:
     virtual bool onDataAvailable(SocketClient* cli);
 
-   private:
+  private:
     static int getLogSocket();
 
     void doSocketDelete(SocketClient* cli);
+
+    LogBuffer* log_buffer_;
+    LogReaderList* reader_list_;
 };