Sync from upstream.

Descriptions:
======================================================================
[FileBackedVector Consolidation][4/x] Fix potential PWrite bug in GrowIfNecessary
======================================================================
[FileBackedVector Consolidation][5/x] Create benchmark for FileBackedVector
======================================================================
[FileBackedVector Consolidation][6/x] Avoid calling GetFileSize in GrowIfNecessary
======================================================================
[PersistentHashMap][3.3/x] Implement Delete
======================================================================
Fix the PopulateMatchedTermsStats bug
======================================================================
Add JNI latency for query latency stats breakdown.
======================================================================
[ResultStateManager] Thread safety test1
======================================================================
[ResultStateManager][2/x] Thread safety test2
======================================================================
Add native lock contention latency for measuring query latency
======================================================================
Fix implementation of HasMember operator in ANTLR-based list-filter prototype.
======================================================================
Fix improper uses of std::string_view
======================================================================
Extend the scale of Icing
======================================================================
Decouple the term frequency array from DocHitInfo
======================================================================
Disable hit_term_frequency for non-relevance queries
======================================================================
[ResultStateManager][3/x] Thread safety test3
======================================================================
[PersistentHashMap][4/x] Implement iterator
=======================================================================
Fix the lite index compaction bug
=======================================================================

Change-Id: I0edad67affed97af107e2d7cd73770e0268c0903

1 files changed, 4 insertions, 2 deletions

diff --git a/icing/util/clock.h b/icing/util/clock.h
index 9e57854..d987a4c 100644
--- a/icing/util/clock.h
+++ b/icing/util/clock.h
@@ -42,12 +42,12 @@ class Timer {
   virtual ~Timer() = default;
 
   // Returns the elapsed time from when timer started.
-  virtual int64_t GetElapsedMilliseconds() {
+  virtual int64_t GetElapsedMilliseconds() const {
     return GetElapsedNanoseconds() / 1000000;
   }
 
   // Returns the elapsed time from when timer started.
-  virtual int64_t GetElapsedNanoseconds() {
+  virtual int64_t GetElapsedNanoseconds() const {
     return GetSteadyTimeNanoseconds() - start_timestamp_nanoseconds_;
   }
 
@@ -90,6 +90,8 @@ class ScopedTimer {
     }
   }
 
+  const Timer& timer() const { return *timer_; }
+
  private:
   std::unique_ptr<Timer> timer_;
   std::function<void(int64_t)> callback_;