Revert of Add synthetic delay testing framework

base/debug/trace_event_synthetic_delay.h

-// Copyright (c) 2013 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.
-
-// The synthetic delay framework makes it possible to dynamically inject
-// arbitrary delays into into different parts of the codebase. This can be used,
-// for instance, for testing various task scheduling algorithms.
-//
-// The delays are specified in terms of a target duration for a given block of
-// code. If the code executes faster than the duration, the thread is made to
-// sleep until the deadline is met.
-//
-// Code can be instrumented for delays with two sets of macros. First, for
-// delays that should apply within a scope, use the following macro:
-//
-//   TRACE_EVENT_SYNTHETIC_DELAY("cc.LayerTreeHost.DrawAndSwap");
-//
-// For delaying operations that span multiple scopes, use:
-//
-//   TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE("cc.Scheduler.BeginMainFrame");
-//   ...
-//   TRACE_EVENT_SYNTHETIC_DELAY_APPLY("cc.Scheduler.BeginMainFrame");
-//
-// Here ACTIVATE establishes the start time for the delay and APPLY executes the
-// delay based on the remaining time. ACTIVATE may be called one or multiple
-// times before APPLY. Only the first call will have an effect. If ACTIVATE
-// hasn't been called since the last call to APPLY, APPLY will be a no-op.
-//
-// Note that while the same delay can be applied in several threads
-// simultaneously, a single delay operation cannot begin on one thread and end
-// on another.
-
-#ifndef BASE_DEBUG_TRACE_EVENT_SYNTHETIC_DELAY_H_
-#define BASE_DEBUG_TRACE_EVENT_SYNTHETIC_DELAY_H_
-
-#include "base/atomicops.h"
-#include "base/debug/trace_event.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/thread_local.h"
-#include "base/time/time.h"
-
-// Apply a named delay in the current scope.
-#define TRACE_EVENT_SYNTHETIC_DELAY(name)                                     \
-  static base::subtle::AtomicWord INTERNAL_TRACE_EVENT_UID(impl_ptr) = 0;     \
-  trace_event_internal::ScopedSyntheticDelay INTERNAL_TRACE_EVENT_UID(delay)( \
-      name, &INTERNAL_TRACE_EVENT_UID(impl_ptr));
-
-// Activate a named delay, establishing its timing start point. May be called
-// multiple times, but only the first call will have an effect.
-#define TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE(name)                       \
-  do {                                                                   \
-    static base::subtle::AtomicWord impl_ptr = 0;                        \
-    trace_event_internal::GetOrCreateDelay(name, &impl_ptr)->Activate(); \
-  } while (false)
-
-// Apply a named delay. If TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE was called for
-// the same delay, that point in time is used as the delay start point. If not,
-// this call will be a no-op.
-#define TRACE_EVENT_SYNTHETIC_DELAY_APPLY(name)                       \
-  do {                                                                \
-    static base::subtle::AtomicWord impl_ptr = 0;                     \
-    trace_event_internal::GetOrCreateDelay(name, &impl_ptr)->Apply(); \
-  } while (false)
-
-template <typename Type>
-struct DefaultSingletonTraits;
-
-namespace base {
-namespace debug {
-
-// Time source for computing delay durations. Used for testing.
-class TRACE_EVENT_API_CLASS_EXPORT TraceEventSyntheticDelayClock {
- public:
-  TraceEventSyntheticDelayClock();
-  virtual ~TraceEventSyntheticDelayClock();
-  virtual base::TimeTicks Now() = 0;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TraceEventSyntheticDelayClock);
-};
-
-// Single delay point instance.
-class TRACE_EVENT_API_CLASS_EXPORT TraceEventSyntheticDelay {
- public:
-  enum Mode {
-    STATIC,      // Apply the configured delay every time.
-    ONE_SHOT,    // Apply the configured delay just once.
-    ALTERNATING  // Apply the configured delay every other time.
-  };
-
-  // Returns an existing named delay instance or creates a new one with |name|.
-  static TraceEventSyntheticDelay* Lookup(const std::string& name);
-
-  void SetTargetDuration(TimeDelta target_duration);
-  void SetMode(Mode mode);
-  void SetClock(TraceEventSyntheticDelayClock* clock);
-
-  // Establish the timing start point for the delay. No-op if the start point
-  // was already set.
-  void Activate();
-
-  // Execute the delay based on the current time and how long ago the start
-  // point was established. If Activate wasn't called, this call will be a
-  // no-op.
-  void Apply();
-
- private:
-  TraceEventSyntheticDelay();
-  ~TraceEventSyntheticDelay();
-  friend class TraceEventSyntheticDelayRegistry;
-
-  void Initialize(const std::string& name,
-                  TraceEventSyntheticDelayClock* clock);
-  void ApplyDelay(base::TimeTicks end_time);
-
-  struct ThreadState {
-    ThreadState();
-
-    base::TimeTicks start_time;
-    unsigned trigger_count;
-    int generation;
-  };
-
-  ThreadState* EnsureThreadState();
-
-  Lock lock_;
-  Mode mode_;
-  std::string name_;
-  int generation_;
-  base::TimeDelta target_duration_;
-  ThreadLocalPointer<ThreadState> thread_state_;
-  TraceEventSyntheticDelayClock* clock_;
-
-  DISALLOW_COPY_AND_ASSIGN(TraceEventSyntheticDelay);
-};
-
-}  // namespace debug
-}  // namespace base
-
-namespace trace_event_internal {
-
-// Helper class for scoped delays. Do not use directly.
-class TRACE_EVENT_API_CLASS_EXPORT ScopedSyntheticDelay {
- public:
-  explicit ScopedSyntheticDelay(const char* name,
-                                base::subtle::AtomicWord* impl_ptr);
-  ~ScopedSyntheticDelay();
-
- private:
-  base::debug::TraceEventSyntheticDelay* delay_impl_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedSyntheticDelay);
-};
-
-// Helper for registering delays. Do not use directly.
-TRACE_EVENT_API_CLASS_EXPORT base::debug::TraceEventSyntheticDelay*
-    GetOrCreateDelay(const char* name, base::subtle::AtomicWord* impl_ptr);
-
-}  // namespace trace_event_internal
-
-#endif /* BASE_DEBUG_TRACE_EVENT_SYNTHETIC_DELAY_H_ */