This fixes a number of things that are warnings in the Mac compiler....

statsreport/formatter.h

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 17 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 
 // Utility class to format metrics to a string suitable for posting to
 // TB stats server.
 #ifndef O3D_STATSREPORT_FORMATTER_H__
 #define O3D_STATSREPORT_FORMATTER_H__
 
-#include <strstream>
+#include <sstream>
 #include "base/basictypes.h"
 #include "metrics.h"
 
 namespace stats_report {
 
 // A utility class that knows how to turn metrics into a string for
 // reporting to the Toolbar stats server.
 class Formatter {
  public:
   // @param name the name of the application to report stats against
   Formatter(const char *name, uint32 measurement_secs);
   ~Formatter();
 
   // Add metric to the output string
   void AddMetric(MetricBase *metric);
 
   // Add typed metrics to the output string
   // @{
   void AddCount(const char *name, uint64 value);
   void AddTiming(const char *name, uint64 num, uint64 avg, uint64 min,
                  uint64 max);
   void AddInteger(const char *name, uint64 value);
   void AddBoolean(const char *name, bool value);
   // @}
 
   // Terminates the output string and returns it.
   // It is an error to add metrics after output() is called.
-  const char *output() {
+  const std::string output() {
     output_ << std::ends;
     return output_.str();
   }
 
  private:
-  mutable std::strstream output_;
+  mutable std::ostringstream output_;
 
   DISALLOW_COPY_AND_ASSIGN(Formatter);
 };
 
 }  // namespace stats_report
 
 #endif  // O3D_STATSREPORT_FORMATTER_H__