Expose RTT and downlink bandwidth using experimental Javascript API

third_party/WebKit/Source/platform/network/NetworkStateNotifier.h

Index: third_party/WebKit/Source/platform/network/NetworkStateNotifier.h
diff --git a/third_party/WebKit/Source/platform/network/NetworkStateNotifier.h b/third_party/WebKit/Source/platform/network/NetworkStateNotifier.h
index a1e80b24014c6728a9172c3dede398ae95a14e22..d0ea645b5bdfbda238978093dac769910449a61b 100644
--- a/third_party/WebKit/Source/platform/network/NetworkStateNotifier.h
+++ b/third_party/WebKit/Source/platform/network/NetworkStateNotifier.h
@@ -33,7 +33,9 @@
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/HashMap.h"
 #include "platform/wtf/Noncopyable.h"
+#include "platform/wtf/Optional.h"
 #include "platform/wtf/ThreadingPrimitives.h"
+#include "platform/wtf/Time.h"
 #include "platform/wtf/Vector.h"
 #include "public/platform/WebConnectionType.h"
 
@@ -51,13 +53,20 @@ class PLATFORM_EXPORT NetworkStateNotifier {
     bool connection_initialized = false;
     WebConnectionType type = kWebConnectionTypeOther;
     double max_bandwidth_mbps = kInvalidMaxBandwidth;
+    Optional<TimeDelta> http_rtt;
+    Optional<TimeDelta> transport_rtt;
+    Optional<double> downlink_throughput_mbps;
   };
 
   class NetworkStateObserver {
    public:
     // Will be called on the task runner that is passed in add*Observer.
-    virtual void ConnectionChange(WebConnectionType,
-                                  double max_bandwidth_mbps) {}
+    virtual void ConnectionChange(
+        WebConnectionType,
+        double max_bandwidth_mbps,
+        const Optional<TimeDelta>& http_rtt,
+        const Optional<TimeDelta>& transport_rtt,
+        const Optional<double>& downlink_throughput_mbps) {}
     virtual void OnLineStateChange(bool on_line) {}
   };
 
@@ -71,6 +80,33 @@ class PLATFORM_EXPORT NetworkStateNotifier {
     return state.on_line;
   }
 
+  // Returns the current HTTP RTT estimate. If the estimate is unavailable, the
+  // returned optional value is null.
+  Optional<TimeDelta> HttpRtt() const {
+    MutexLocker locker(mutex_);
+    const NetworkState& state = has_override_ ? override_ : state_;
+    DCHECK(state.on_line_initialized);
+    return state.http_rtt;
+  }
+
+  // Returns the current transport RTT estimate. If the estimate is unavailable,
+  // the returned optional value is null.
+  Optional<TimeDelta> TransportRtt() const {
+    MutexLocker locker(mutex_);
+    const NetworkState& state = has_override_ ? override_ : state_;
+    DCHECK(state.on_line_initialized);
+    return state.transport_rtt;
+  }
+
+  // Returns the current throughput estimate (in megabits per second). If the
+  // estimate is unavailable, the returned optional value is null.
+  Optional<double> DownlinkThroughputMbps() const {
+    MutexLocker locker(mutex_);
+    const NetworkState& state = has_override_ ? override_ : state_;
+    DCHECK(state.on_line_initialized);
+    return state.downlink_throughput_mbps;
+  }
+
   void SetOnLine(bool);
 
   // Can be called on any thread.
@@ -110,6 +146,9 @@ class PLATFORM_EXPORT NetworkStateNotifier {
   }
 
   void SetWebConnection(WebConnectionType, double max_bandwidth_mbps);
+  void SetWebNetworkQuality(int http_rtt_msec,

[kinuko, 2017/05/17 02:05:45]

Just SetNetworkQuality ? 'WebNetworkQuality' doesn't seem to make a lot sense.

[tbansal1, 2017/05/17 05:25:26]

Done.

+                            int transport_rtt_msec,
+                            int downlink_throughput_kbps);
 
   // When called, successive setWebConnectionType/setOnLine calls are stored,
   // and supplied overridden values are used instead until clearOverride() is