Use overloaded operators with QuicTime for addition, subtraction and scalar

net/quic/congestion_control/windowed_filter.h

Index: net/quic/congestion_control/windowed_filter.h
diff --git a/net/quic/congestion_control/windowed_filter.h b/net/quic/congestion_control/windowed_filter.h
index 9c2ce1a894266b9396e0252b8418e0346f3924de..65dd866cb8ee27e8a99a859a4ccf7270239178f0 100644
--- a/net/quic/congestion_control/windowed_filter.h
+++ b/net/quic/congestion_control/windowed_filter.h
@@ -73,7 +73,7 @@ class WindowedFilter {
     // is a new best, or if the newest recorded estimate is too old.
     if (estimates_[0].sample == zero_value_ ||
         Compare()(new_sample, estimates_[0].sample) ||
-        new_time.Subtract(estimates_[2].time) > window_length_) {
+        new_time - estimates_[2].time > window_length_) {
       Reset(new_sample, new_time);
       return;
     }
@@ -86,7 +86,7 @@ class WindowedFilter {
     }
 
     // Expire and update estimates as necessary.
-    if (new_time.Subtract(estimates_[0].time) > window_length_) {
+    if (new_time - estimates_[0].time > window_length_) {
       // The best estimate hasn't been updated for an entire window, so promote
       // second and third best estimates.
       estimates_[0] = estimates_[1];
@@ -96,14 +96,14 @@ class WindowedFilter {
       // outside the window as well, since it may also have been recorded a
       // long time ago. Don't need to iterate once more since we cover that
       // case at the beginning of the method.
-      if (new_time.Subtract(estimates_[0].time) > window_length_) {
+      if (new_time - estimates_[0].time > window_length_) {
         estimates_[0] = estimates_[1];
         estimates_[1] = estimates_[2];
       }
       return;
     }
     if (estimates_[1].sample == estimates_[0].sample &&
-        new_time.Subtract(estimates_[1].time) > window_length_ >> 2) {
+        new_time - estimates_[1].time > window_length_ >> 2) {
       // A quarter of the window has passed without a better sample, so the
       // second-best estimate is taken from the second quarter of the window.
       estimates_[2] = estimates_[1] = Sample(new_sample, new_time);
@@ -111,7 +111,7 @@ class WindowedFilter {
     }
 
     if (estimates_[2].sample == estimates_[1].sample &&
-        new_time.Subtract(estimates_[2].time) > window_length_ >> 1) {
+        new_time - estimates_[2].time > window_length_ >> 1) {
       // We've passed a half of the window without a better estimate, so take
       // a third-best estimate from the second half of the window.
       estimates_[2] = Sample(new_sample, new_time);