Improve timeline iterators and tests

runtime/vm/timeline_analysis.h

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_TIMELINE_ANALYSIS_H_
 #define VM_TIMELINE_ANALYSIS_H_
 
 #include "vm/growable_array.h"
 #include "vm/timeline.h"
 
@@ skipping 20 matching lines @@
   void AddBlock(TimelineEventBlock* block);
   void Finalize();
 
   const ThreadId id_;
   ZoneGrowableArray<TimelineEventBlock*> blocks_;
 
   friend class TimelineAnalysis;
 };
 
 
+class TimelineAnalysisThreadEventIterator : public ValueObject {
+ public:
+  explicit TimelineAnalysisThreadEventIterator(TimelineAnalysisThread* thread);
+  ~TimelineAnalysisThreadEventIterator();
+
+  void Reset(TimelineAnalysisThread* thread);
+
+  bool HasNext() const;
+
+  TimelineEvent* Next();
+
+ private:
+  TimelineAnalysisThread* thread_;
+  TimelineEvent* current_;
+  intptr_t block_cursor_;
+  intptr_t event_cursor_;
+};
+
+
 // Base of all timeline analysis classes. Base functionality:
 // - discovery of all thread ids in a recording.
 // - collecting all ThreadEventBlocks by thread id.
 class TimelineAnalysis : public ValueObject {
  public:
   TimelineAnalysis(Zone* zone,
                    Isolate* isolate,
                    TimelineEventRecorder* recorder);
   ~TimelineAnalysis();
 
@@ skipping 33 matching lines @@
 
   ZoneGrowableArray<TimelineAnalysisThread*> threads_;
 };
 
 
 class TimelinePauses : public TimelineAnalysis {
  public:
   TimelinePauses(Zone* zone,
                  Isolate* isolate,
                  TimelineEventRecorder* recorder);
+
+  void CalculatePauseTimes();
+
  private:
 };
 
 }  // namespace dart
 
 #endif  // VM_TIMELINE_ANALYSIS_H_