[NetInfo] Add Blink support for connection.change, connection.downlinkMax, and wimax

Source/modules/netinfo/NetworkInformation.cpp

Index: Source/modules/netinfo/NetworkInformation.cpp
diff --git a/Source/modules/netinfo/NetworkInformation.cpp b/Source/modules/netinfo/NetworkInformation.cpp
index a3596e340419781a12f531e405c9263381be5534..696d90829db621384bef64ffaca74e7aea783fa6 100644
--- a/Source/modules/netinfo/NetworkInformation.cpp
+++ b/Source/modules/netinfo/NetworkInformation.cpp
@@ -9,6 +9,7 @@
 #include "core/events/Event.h"
 #include "core/page/NetworkStateNotifier.h"
 #include "modules/EventTargetModules.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "wtf/text/WTFString.h"
 
 namespace {
@@ -26,6 +27,8 @@ String connectionTypeToString(WebConnectionType type)
         return "ethernet";
     case ConnectionTypeWifi:
         return "wifi";
+    case ConnectionTypeWimax:
+        return "wimax";
     case ConnectionTypeOther:
         return "other";
     case ConnectionTypeNone:
@@ -64,17 +67,29 @@ String NetworkInformation::type() const
     return connectionTypeToString(m_type);
 }
 
-void NetworkInformation::connectionTypeChange(WebConnectionType type)
+double NetworkInformation::downlinkMax() const
+{
+    if (!m_observing)
+        return networkStateNotifier().maxBandwidth();
+
+    return m_downlinkMax;
+}
+
+void NetworkInformation::connectionChange(WebConnectionType type, double downlinkMax)
 {
     ASSERT(executionContext()->isContextThread());
 
     // This can happen if the observer removes and then adds itself again
     // during notification.
-    if (m_type == type)
+    if (m_type == type && m_downlinkMax == downlinkMax)
         return;
 
     m_type = type;
+    m_downlinkMax = downlinkMax;
     dispatchEvent(Event::create(EventTypeNames::typechange));
+
+    if (RuntimeEnabledFeatures::netInfoDownlinkMaxEnabled())
+        dispatchEvent(Event::create(EventTypeNames::change));
 }
 
 const AtomicString& NetworkInformation::interfaceName() const
@@ -145,6 +160,7 @@ void NetworkInformation::stopObserving()
 NetworkInformation::NetworkInformation(ExecutionContext* context)
     : ActiveDOMObject(context)
     , m_type(networkStateNotifier().connectionType())
+    , m_downlinkMax(networkStateNotifier().maxBandwidth())
     , m_observing(false)
     , m_contextStopped(false)
 {