[UMA] Add performance profile data to UMA uploads.

base/profiler/alternate_timer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is a glue file, which allows third party code to call into our profiler
 // without having to include most any functions from base.
 
-
 #ifndef BASE_PROFILER_ALTERNATE_TIMER_H_
 #define BASE_PROFILER_ALTERNATE_TIMER_H_
 
+#include "base/base_export.h"
+
 namespace tracked_objects {
 
 // Provide type for an alternate timer function.
 typedef unsigned int NowFunction();
 
-// Set an alternate timer function to replace the OS time function when
-// profiling.  Typically this is called by an allocator that is providing a
-// function that indicates how much memory has been allocated on any given
-// thread.
-extern void SetAlternateTimeSource(NowFunction* now_function);
-
-// Gets the pointer to a function that was set via SetAlternateTimeSource().
-// Returns NULL if no set was done prior to calling GetAlternateTimeSource.
-extern NowFunction* GetAlternateTimeSource();
-
 // Environment variable name that is used to activate alternate timer profiling
 // (such as using TCMalloc allocations to provide a pseudo-timer) for tasks
 // instead of wall clock profiling.
 extern const char kAlternateProfilerTime[];
 
+// Set an alternate timer function to replace the OS time function when
+// profiling.  Typically this is called by an allocator that is providing a
+// function that indicates how much memory has been allocated on any given
+// thread.
+void SetAlternateTimeSource(NowFunction* now_function);
 
+// Gets the pointer to a function that was set via SetAlternateTimeSource().
+// Returns NULL if no set was done prior to calling GetAlternateTimeSource.
+BASE_EXPORT NowFunction* GetAlternateTimeSource();
 
-}  // tracked_objects
+}  // namespace tracked_objects
 
 #endif  // BASE_PROFILER_ALTERNATE_TIMER_H_