[DevTools] Network.emulateNetworkConditions now affects NetworkStateNotifier.

third_party/WebKit/Source/core/page/NetworkStateNotifier.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
 class CORE_EXPORT NetworkStateNotifier {
     WTF_MAKE_NONCOPYABLE(NetworkStateNotifier); USING_FAST_MALLOC(NetworkStateNotifier);
 public:
     class NetworkStateObserver {
     public:
         // Will be called on the thread of the context passed in addObserver.
         virtual void connectionChange(WebConnectionType, double maxBandwidthMbps) = 0;
     };
 
     NetworkStateNotifier()
-        : m_initialized(false)
-        , m_isOnLine(true)
-        , m_type(WebConnectionTypeOther)
-        , m_maxBandwidthMbps(kInvalidMaxBandwidth)
-        , m_testUpdatesOnly(false)
+        : m_hasOverride(false)
     {
     }
 
     // Can be called on any thread.
     bool onLine() const
     {
         MutexLocker locker(m_mutex);
-        ASSERT(m_initialized);
-        return m_isOnLine;
+        const NetworkState& data = m_hasOverride ? m_override : m_state;
+        DCHECK(data.onLineInitialized);
+        return data.onLine;
     }
 
     void setOnLine(bool);
 
     // Can be called on any thread.
     WebConnectionType connectionType() const
     {
         MutexLocker locker(m_mutex);
-        ASSERT(m_initialized);
-        return m_type;
+        const NetworkState& data = m_hasOverride ? m_override : m_state;
+        DCHECK(data.connectionInitialized);
+        return data.type;
     }
 
     // Can be called on any thread.
     bool isCellularConnectionType() const
     {
         switch (connectionType()) {
         case WebConnectionTypeCellular2G:
         case WebConnectionTypeCellular3G:
         case WebConnectionTypeCellular4G:
             return true;
         case WebConnectionTypeBluetooth:
         case WebConnectionTypeEthernet:
         case WebConnectionTypeWifi:
         case WebConnectionTypeWimax:
         case WebConnectionTypeOther:
         case WebConnectionTypeNone:
         case WebConnectionTypeUnknown:
             return false;
         }
         ASSERT_NOT_REACHED();
         return false;
     }
 
     // Can be called on any thread.
     double maxBandwidth() const
     {
         MutexLocker locker(m_mutex);
-        ASSERT(m_initialized);
-        return m_maxBandwidthMbps;
+        const NetworkState& data = m_hasOverride ? m_override : m_state;
+        DCHECK(data.connectionInitialized);
+        return data.maxBandwidthMbps;
     }
 
     void setWebConnection(WebConnectionType, double maxBandwidthMbps);
 
+    // When called, successive setWebConnectionType/setOnLine calls are ignored,

[jkarlin, 2016/06/28 17:57:12]

Hmm, not quite ignored, since they're stored and will be used again once
clearOverride() is called.

Perhaps:

"are stored, and supplied overridden values are used instead until
clearOverride() is called."

[dgozman, 2016/06/29 01:17:33]

Done.

+    // and supplied overridden values are used instead.
+    // This is used for layout tests (see crbug.com/377736) and inspector emulation.
+    //
+    // Since this class is a singleton, tests must clear override when completed to
+    // avoid indeterminate state across the test harness. When switching in or out of test
+    // mode, all state will be reset to default values.

[jkarlin, 2016/06/28 17:57:12]

This last sentence is no longer true.

[dgozman, 2016/06/29 01:17:33]

Good catch! Done.

+    void setOverride(bool onLine, WebConnectionType, double maxBandwidthMbps);
+    void clearOverride();
+
     // Must be called on the context's thread. An added observer must be removed
     // before its ExecutionContext is deleted. It's possible for an observer to
     // be called twice for the same event if it is first removed and then added
     // during notification.
     void addObserver(NetworkStateObserver*, ExecutionContext*);
     void removeObserver(NetworkStateObserver*, ExecutionContext*);
 
-    // The following functions are for testing purposes.
-
-    // When true, setWebConnectionType calls are ignored and only setWebConnectionTypeForTest
-    // can update the connection type. This is used for layout tests (see crbug.com/377736).
-    //
-    // Since this class is a singleton, tests must call this with false when completed to
-    // avoid indeterminate state across the test harness. When switching in or out of test
-    // mode, all state will be reset to default values.
-    void setTestUpdatesOnly(bool);
-    // Tests should call this as it will change the type regardless of the value of m_testUpdatesOnly.
-    void setWebConnectionForTest(WebConnectionType, double maxBandwidthMbps);
-
 private:
     struct ObserverList {
         ObserverList()
             : iterating(false)
         {
         }
         bool iterating;
         Vector<NetworkStateObserver*> observers;
         Vector<size_t> zeroedObservers; // Indices in observers that are 0.
     };
 
-    const int kInvalidMaxBandwidth = -1;
+    struct NetworkState {
+        static const int kInvalidMaxBandwidth = -1;
+        bool onLineInitialized = false;
+        bool onLine = true;
+        bool connectionInitialized = false;
+        WebConnectionType type = WebConnectionTypeOther;
+        double maxBandwidthMbps = kInvalidMaxBandwidth;
+    };
 
-    void setWebConnectionImpl(WebConnectionType, double maxBandwidthMbps);
-    void setMaxBandwidthImpl(double maxBandwidthMbps);
+    // This helper scope acquires the lock to access the members of NetworkStateNotifier
+    // and issues required notifications when mutating the state, if something changed.
+    // It's only possible to mutate the state on main thread.

[jkarlin, 2016/06/28 17:57:12]

s/on main thread/on the main thread/

[dgozman, 2016/06/29 01:17:33]

Done.

+    class ScopedNotifier {
+    public:
+        explicit ScopedNotifier(NetworkStateNotifier&);
+        ~ScopedNotifier();
+    private:
+        NetworkStateNotifier& m_notifier;
+        NetworkState m_before;
+    };
 
     // The ObserverListMap is cross-thread accessed, adding/removing Observers running
     // within an ExecutionContext. Kept off-heap to ease cross-thread allocation and use;
     // the observers are (already) responsible for explicitly unregistering while finalizing.
     using ObserverListMap = HashMap<UntracedMember<ExecutionContext>, std::unique_ptr<ObserverList>>;
 
+    void notifyObservers(WebConnectionType, double maxBandwidthMbps);
     void notifyObserversOfConnectionChangeOnContext(WebConnectionType, double maxBandwidthMbps, ExecutionContext*);
 
     ObserverList* lockAndFindObserverList(ExecutionContext*);
 
     // Removed observers are nulled out in the list in case the list is being
     // iterated over. Once done iterating, call this to clean up nulled
     // observers.
     void collectZeroedObservers(ObserverList*, ExecutionContext*);
 
     mutable Mutex m_mutex;
-    bool m_initialized;
-    bool m_isOnLine;
-    WebConnectionType m_type;
-    double m_maxBandwidthMbps;
+    NetworkState m_state;
+    bool m_hasOverride;
+    NetworkState m_override;
     ObserverListMap m_observers;
-    bool m_testUpdatesOnly;
 };
 
 CORE_EXPORT NetworkStateNotifier& networkStateNotifier();
 
 } // namespace blink
 
 #endif // NetworkStateNotifier_h