Revert three commits due to cpu-profiler failures

src/profiler/tick-sample.h

 // Copyright 2013 the V8 project 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 V8_PROFILER_TICK_SAMPLE_H_
 #define V8_PROFILER_TICK_SAMPLE_H_
 
 #include "include/v8-profiler.h"
 #include "src/base/platform/time.h"
 #include "src/globals.h"
 
 namespace v8 {
 namespace internal {
 
 class Isolate;
 
 struct TickSample : public v8::TickSample {
+  TickSample() : v8::TickSample() {}
   void Init(Isolate* isolate, const v8::RegisterState& state,
             RecordCEntryFrame record_c_entry_frame, bool update_stats);
   base::TimeTicks timestamp;
 };
 
+#if defined(USE_SIMULATOR)
+class SimulatorHelper {
+ public:
+  // Returns true if register values were successfully retrieved
+  // from the simulator, otherwise returns false.
+  static bool FillRegisters(Isolate* isolate, v8::RegisterState* state);
+};
+#endif  // USE_SIMULATOR
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PROFILER_TICK_SAMPLE_H_