Add connection type to NCN::MaxBandwidthChanged

net/base/network_change_notifier.h

Index: net/base/network_change_notifier.h
diff --git a/net/base/network_change_notifier.h b/net/base/network_change_notifier.h
index abced4859a29857b493bf52012a0041ad6c9828b..97a2354ef39212a6ae981930a1734a9945fc9a4f 100644
--- a/net/base/network_change_notifier.h
+++ b/net/base/network_change_notifier.h
@@ -186,14 +186,12 @@ class NET_EXPORT NetworkChangeNotifier {
 
   class NET_EXPORT MaxBandwidthObserver {
    public:
-    // Will be called when a change occurs to the network's maximum bandwidth as
-    // defined in http://w3c.github.io/netinfo/. Generally this will only be
-    // called on bandwidth changing network connection/disconnection events.
-    // Some platforms may call it more frequently, such as when WiFi signal
-    // strength changes.
-    // TODO(jkarlin): This is currently only implemented for Android. Implement
-    // on every platform.
-    virtual void OnMaxBandwidthChanged(double max_bandwidth_mbps) = 0;
+    // Called when a change occurs to the network's maximum bandwidth as
+    // defined in http://w3c.github.io/netinfo/. Also called on type change,
+    // even if the maximum bandwidth doesn't change. See the documentation of
+    // GetMaxBanwidth for what to expect for the values of |max_bandwidth_mbps|.
+    virtual void OnMaxBandwidthChanged(ConnectionType type,
+                                       double max_bandwidth_mbps) = 0;
 
    protected:
     MaxBandwidthObserver() {}
@@ -235,12 +233,16 @@ class NET_EXPORT NetworkChangeNotifier {
   static ConnectionType GetConnectionType();
 
   // Returns a theoretical upper limit on download bandwidth, potentially based
-  // on underlying connection type, signal strength, or some other signal. The
-  // default mapping of connection type to maximum bandwidth is provided in the
-  // NetInfo spec: http://w3c.github.io/netinfo/. Host-specific application
-  // permissions may be required, please see host-specific declaration for more
-  // information.
-  static double GetMaxBandwidth();
+  // on underlying connection type, signal strength, or some other signal.
+  // Specifically, it returns +Infinity if there is a connection and 0.0
+  // otherwise. The circumstances in which a more specific value is given are:
+  // Android cellular types, Android wifi types, and ChromeOS cellular types.
+  // See the NetInfo spec for the mapping of specific subtypes to bandwidth
+  // values: http://w3c.github.io/netinfo/.
+  // If |connection_type| is not nullptr then it is set to the
+  // current ConnectionType.
+  static double GetMaxBandwidthAndConnectionType(
+      ConnectionType* connection_type);

[pauljensen, 2015/09/11 18:59:02]

Are you going to change this API to take pointers to both items as per our char
earlier?

[jkarlin, 2015/09/11 19:04:26]

Ah, I took our convo. to mean that you were fine with either arrangement. I
chose this one form so that I could
DCHECK(GetMaxBandwidthAndConnectionType(nullptr) != ...) which is needed in one
of the files. 

[pauljensen, 2015/09/11 19:18:59]

Oh, no, I was trying to say I wanted it to be:
void GetMaxBandwidthAndConnectionType(double* max_bandwidth_mbps,
ConnectionType* connection_type);
Sorry.  It seems more consistent to me.

[jkarlin, 2015/09/11 20:07:24]

Done.

 
   // Retrieve the last read DnsConfig. This could be expensive if the system has
   // a large HOSTS file.
@@ -309,6 +311,8 @@ class NET_EXPORT NetworkChangeNotifier {
       ConnectionType type);
   static void NotifyObserversOfNetworkChangeForTests(ConnectionType type);
   static void NotifyObserversOfInitialDNSConfigReadForTests();
+  static void NotifyObserversOfMaxBandwidthChangeForTests(ConnectionType type,
+                                                          double max_bandwidth);
 
   // Enable or disable notifications from the host. After setting to true, be
   // sure to pump the RunLoop until idle to finish any preexisting
@@ -392,7 +396,8 @@ class NET_EXPORT NetworkChangeNotifier {
   // See the description of NetworkChangeNotifier::GetMaxBandwidth().
   // Implementations must be thread-safe. Implementations must also be
   // cheap as it is called often.
-  virtual double GetCurrentMaxBandwidth() const;
+  virtual double GetCurrentMaxBandwidthAndConnectionType(
+      ConnectionType* connection_type) const;

[pauljensen, 2015/09/11 18:59:02]

ditto

[jkarlin, 2015/09/11 20:07:23]

Done.

 
   // Returns a theoretical upper limit on download bandwidth given a connection
   // subtype. The mapping of connection type to maximum bandwidth is provided in
@@ -407,7 +412,8 @@ class NET_EXPORT NetworkChangeNotifier {
   static void NotifyObserversOfDNSChange();
   static void NotifyObserversOfInitialDNSConfigRead();
   static void NotifyObserversOfNetworkChange(ConnectionType type);
-  static void NotifyObserversOfMaxBandwidthChange(double max_bandwidth_mbps);
+  static void NotifyObserversOfMaxBandwidthChange(ConnectionType type,
+                                                  double max_bandwidth_mbps);
 
   // Stores |config| in NetworkState and notifies OnDNSChanged observers.
   static void SetDnsConfig(const DnsConfig& config);
@@ -429,7 +435,8 @@ class NET_EXPORT NetworkChangeNotifier {
   void NotifyObserversOfDNSChangeImpl();
   void NotifyObserversOfInitialDNSConfigReadImpl();
   void NotifyObserversOfNetworkChangeImpl(ConnectionType type);
-  void NotifyObserversOfMaxBandwidthChangeImpl(double max_bandwidth_mbps);
+  void NotifyObserversOfMaxBandwidthChangeImpl(ConnectionType type,
+                                               double max_bandwidth_mbps);
 
   const scoped_refptr<base::ObserverListThreadSafe<IPAddressObserver>>
       ip_address_observer_list_;