Add hook for developers to play with profiler (unofficially)

base/profiler/scoped_profile.h

 // Copyright (c) 2011 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.
 
 
 #ifndef BASE_PROFILER_SCOPED_PROFILE_H_
 #define BASE_PROFILER_SCOPED_PROFILE_H_
 
 //------------------------------------------------------------------------------
 // ScopedProfile provides basic helper functions for profiling a short
 // region of code within a scope.  It is separate from the related ThreadData
 // class so that it can be included without much other cruft, and provide the
 // macros listed below.
 
 #include "base/base_export.h"
 #include "base/location.h"
 #include "base/profiler/tracked_time.h"
 
-#define TRACK_RUN_IN_THIS_SCOPED_REGION_FOR_OFFICIAL_BUILDS(variable_name) \
-    ::tracked_objects::ScopedProfile variable_name(FROM_HERE)
+#if defined(GOOGLE_CHROME_BUILD)
 
-#define TRACK_RUN_IN_IPC_HANDLER(dispatch_function_name) \
-    ::tracked_objects::ScopedProfile some_tracking_variable_name(  \
+// We don't ship these profiled regions.  This is for developer builds only.
+// It allows developers to do some profiling of their code, and see results on
+// their about:profiler page.
+#define TRACK_RUN_IN_THIS_SCOPED_REGION_FOR_DEVELOPER_BUILDS(scope_name)       \
+    ((void)0)
+
+#else
+
+#define TRACK_RUN_IN_THIS_SCOPED_REGION_FOR_DEVELOPER_BUILDS(scope_name)       \
+    ::tracked_objects::ScopedProfile  LINE_BASED_VARIABLE_NAME_FOR_PROFILING(  \
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(#scope_name))
+
+#endif
+
+
+
+#define PASTE_LINE_NUMBER_ON_NAME(name, line) name##line
+
+#define LINE_BASED_VARIABLE_NAME_FOR_PROFILING                                 \
+    PASTE_LINE_NUMBER_ON_NAME(some_profiler_variable_, __LINE__)
+
+#define TRACK_RUN_IN_IPC_HANDLER(dispatch_function_name)                       \
+    ::tracked_objects::ScopedProfile some_tracking_variable_name(              \
         FROM_HERE_WITH_EXPLICIT_FUNCTION(#dispatch_function_name))
 
 
 namespace tracked_objects {
 class Births;
 
 class BASE_EXPORT ScopedProfile {
  public:
   explicit ScopedProfile(const Location& location);
   ~ScopedProfile();
 
   // Stop tracing prior to the end destruction of the instance.
   void StopClockAndTally();
 
  private:
   Births* birth_;  // Place in code where tracking started.
   const TrackedTime start_of_run_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedProfile);
 };
 
 }  // namespace tracked_objects
 
 #endif   // BASE_PROFILER_SCOPED_PROFILE_H_