Remove lock from remoting::RunningAverage

The class is always used on the same thread, so it doesn't need to be
thread-safe.

Review URL: https://codereview.chromium.org/1351253002

Cr-Commit-Position: refs/heads/master@{#349746}

2 files changed, 10 insertions, 12 deletions

diff --git a/remoting/base/running_average.cc b/remoting/base/running_average.cc
index 83877dc..5e24c0d 100644
--- a/remoting/base/running_average.cc
+++ b/remoting/base/running_average.cc
@@ -14,11 +14,10 @@ RunningAverage::RunningAverage(int window_size)
   DCHECK_GT(window_size, 0);
 }
 
-RunningAverage::~RunningAverage() {
-}
+RunningAverage::~RunningAverage() {}
 
-void RunningAverage::Record(int64 value) {
-  base::AutoLock auto_lock(lock_);
+void RunningAverage::Record(int64_t value) {
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   data_points_.push_back(value);
   sum_ += value;
@@ -30,7 +29,7 @@ void RunningAverage::Record(int64 value) {
 }
 
 double RunningAverage::Average() {
-  base::AutoLock auto_lock(lock_);
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   if (data_points_.empty())
     return 0;
diff --git a/remoting/base/running_average.h b/remoting/base/running_average.h
index 633659d..2ed2115 100644
--- a/remoting/base/running_average.h
+++ b/remoting/base/running_average.h
@@ -8,7 +8,7 @@
 #include <deque>
 
 #include "base/basictypes.h"
-#include "base/synchronization/lock.h"
+#include "base/threading/thread_checker.h"
 
 namespace remoting {
 
@@ -22,7 +22,7 @@ class RunningAverage {
   virtual ~RunningAverage();
 
   // Records a point sample.
-  void Record(int64 value);
+  void Record(int64_t value);
 
   // Returns the average over up to |window_size| of the most recent samples.
   double Average();
@@ -32,14 +32,13 @@ class RunningAverage {
   // with the size of |data_points_|.
   const size_t window_size_;
 
-  // Protects |data_points_| and |sum_|.
-  base::Lock lock_;
-
   // Stores the |window_size| most recently recorded samples.
-  std::deque<int64> data_points_;
+  std::deque<int64_t> data_points_;
 
   // Holds the sum of the samples in |data_points_|.
-  int64 sum_;
+  int64_t sum_;
+
+  base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(RunningAverage);
 };