test IWYU fixups for base

base/tracked_objects.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.
 
 #ifndef BASE_TRACKED_OBJECTS_H_
 #define BASE_TRACKED_OBJECTS_H_
 
 #include <map>
 #include <set>
 #include <stack>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/base_export.h"
+#include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/lazy_instance.h"
 #include "base/location.h"
 #include "base/profiler/alternate_timer.h"
 #include "base/profiler/tracked_time.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_local_storage.h"
-#include "base/tracking_info.h"
+
+namespace base {
+struct TrackingInfo;
+}
 
 // TrackedObjects provides a database of stats about objects (generally Tasks)
 // that are tracked.  Tracking means their birth, death, duration, birth thread,
 // death thread, and birth place are recorded.  This data is carefully spread
 // across a series of objects so that the counts and times can be rapidly
 // updated without (usually) having to lock the data, and hence there is usually
 // very little contention caused by the tracking.  The data can be viewed via
 // the about:profiler URL, with a variety of sorting and filtering choices.
 //
 // These classes serve as the basis of a profiler of sorts for the Tasks system.
@@ skipping 674 matching lines @@
   ~ProcessDataSnapshot();
 
   std::vector<TaskSnapshot> tasks;
   std::vector<ParentChildPairSnapshot> descendants;
   int process_id;
 };
 
 }  // namespace tracked_objects
 
 #endif  // BASE_TRACKED_OBJECTS_H_