[Android] Add animation frame time histogram class.

base/time/time.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.
 
 // Time represents an absolute point in coordinated universal time (UTC),
 // internally represented as microseconds (s/1,000,000) since the Windows epoch
 // (1601-01-01 00:00:00 UTC) (See http://crbug.com/14734).  System-dependent
 // clock interface routines are defined in time_PLATFORM.cc.
 //
 // TimeDelta represents a duration of time, internally represented in
@@ skipping 57 matching lines @@
 
   // Converts units of time to TimeDeltas.
   static TimeDelta FromDays(int days);
   static TimeDelta FromHours(int hours);
   static TimeDelta FromMinutes(int minutes);
   static TimeDelta FromSeconds(int64 secs);
   static TimeDelta FromMilliseconds(int64 ms);
   static TimeDelta FromSecondsD(double secs);
   static TimeDelta FromMillisecondsD(double ms);
   static TimeDelta FromMicroseconds(int64 us);
+  static TimeDelta FromNanoseconds(int64 ns);
 #if defined(OS_WIN)
   static TimeDelta FromQPCValue(LONGLONG qpc_value);
 #endif
 
   // Converts an integer value representing TimeDelta to a class. This is used
   // when deserializing a |TimeDelta| structure, using a value known to be
   // compatible. It is not provided as a constructor because the integer type
   // may be unclear from the perspective of a caller.
   static TimeDelta FromInternalValue(int64 delta) {
     return TimeDelta(delta);
@@ skipping 480 matching lines @@
 }
 
 // static
 inline TimeDelta TimeDelta::FromMicroseconds(int64 us) {
   // Preserve max to prevent overflow.
   if (us == std::numeric_limits<int64>::max())
     return Max();
   return TimeDelta(us);
 }
 
+// static
+inline TimeDelta TimeDelta::FromNanoseconds(int64 ns) {
+  // Preserve max to prevent overflow.
+  if (ns == std::numeric_limits<int64>::max())
+    return Max();
+  return TimeDelta(ns / Time::kNanosecondsPerMicrosecond);
+}
+
 inline Time TimeDelta::operator+(Time t) const {
   return Time(t.us_ + delta_);
 }
 
 // For logging use only.
 BASE_EXPORT std::ostream& operator<<(std::ostream& os, Time time);
 
 // TimeTicks ------------------------------------------------------------------
 
 class BASE_EXPORT TimeTicks {
@@ skipping 166 matching lines @@
 inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
   return TimeTicks(t.ticks_ + delta_);
 }
 
 // For logging use only.
 BASE_EXPORT std::ostream& operator<<(std::ostream& os, TimeTicks time_ticks);
 
 }  // namespace base
 
 #endif  // BASE_TIME_TIME_H_