[DevTools] Network.emulateNetworkConditions now affects NetworkStateNotifier.

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

Index: third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp
diff --git a/third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp b/third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp
index 628b377de6a04f3f2954bf2f6754bb7eb38ceb58..d7b8e08af3a86ec1f9411d8834c60197a53bb41c 100644
--- a/third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp
+++ b/third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp
@@ -42,28 +42,43 @@ NetworkStateNotifier& networkStateNotifier()
     return networkStateNotifier;
 }
 
-void NetworkStateNotifier::setOnLine(bool onLine)
+void NetworkStateNotifier::setOnLine(bool onLineValue)
 {
-    ASSERT(isMainThread());
+    DCHECK(isMainThread());
 
     {
         MutexLocker locker(m_mutex);
-        if (m_isOnLine == onLine)
+        m_onLineInitialized = true;
+
+        if (m_isOnLine == onLineValue)
             return;
+        m_isOnLine = onLineValue;
 
-        m_isOnLine = onLine;
+        if (m_hasOverride)
+            return;
     }
 
-    Page::networkStateChanged(onLine);
+    Page::networkStateChanged(onLine());
 }
 
 void NetworkStateNotifier::setWebConnection(WebConnectionType type, double maxBandwidthMbps)
 {
-    ASSERT(isMainThread());
-    if (m_testUpdatesOnly)
-        return;
+    DCHECK(isMainThread());
+
+    {
+        MutexLocker locker(m_mutex);
+        m_connectionInitialized = true;
+
+        if (m_type == type && m_maxBandwidthMbps == maxBandwidthMbps)
+            return;
+        m_type = type;
+        m_maxBandwidthMbps = maxBandwidthMbps;
+
+        if (m_hasOverride)
+            return;
+    }
 
-    setWebConnectionImpl(type, maxBandwidthMbps);
+    notifyObservers();
 }
 
 void NetworkStateNotifier::addObserver(NetworkStateObserver* observer, ExecutionContext* context)
@@ -100,40 +115,42 @@ void NetworkStateNotifier::removeObserver(NetworkStateObserver* observer, Execut
         collectZeroedObservers(observerList, context);
 }
 
-void NetworkStateNotifier::setTestUpdatesOnly(bool updatesOnly)
+void NetworkStateNotifier::setOverride(bool onLineValue, WebConnectionType type, double maxBandwidthMbps)
 {
-    ASSERT(isMainThread());
-    MutexLocker locker(m_mutex);
+    DCHECK(isMainThread());
 
-    // Reset state to default when entering or leaving test mode.
-    if (updatesOnly != m_testUpdatesOnly) {
-        m_isOnLine = true;
-        m_type = WebConnectionTypeOther;
-        m_maxBandwidthMbps = std::numeric_limits<double>::infinity();
+    {
+        MutexLocker locker(m_mutex);
+        m_hasOverride = true;
+        m_overrideOnLine = onLineValue;
+        m_overrideType = type;
+        m_overrideMaxBandwidthMbps = maxBandwidthMbps;
     }
 
-    m_testUpdatesOnly = updatesOnly;
+    notifyObservers();
+    Page::networkStateChanged(onLine());

[jkarlin, 2016/06/24 14:47:50]

setOnline and setWebConnection check if anything has actually changed before
sending out notification. This should as well.

[dgozman, 2016/06/24 15:13:44]

I think this would be undesirable. Consider two cases it's used:
- Tests. Here we cannot rely on the previous values (they can be arbitrary). And
if the test expects an event to be fired, event should fire no matter what.
- DevTools emulation. Here user expects an event to fire after an explicit
action. If it fires at some times and not the others, it would be perceived as
unreliable.

[jkarlin, 2016/06/24 19:20:16]

The clients of NetworkStateNotifier (e.g., the online event) don't expect to get
repeat values. Firing onLine twice without first calling offLine isn't spec'd
behavior.

If tests need an event, they can set it to one value and then another, the
second will trigger an event. That's what the existing tests do.
Do they? If my device is onLine and I change to 2G, I wouldn't expect to receive
an onLine event.

[dgozman, 2016/06/27 23:03:49]

Alright, you convinced me. Can't go against the spec.

 }
 
-void NetworkStateNotifier::setWebConnectionForTest(WebConnectionType type, double maxBandwidthMbps)
+void NetworkStateNotifier::clearOverride()
 {
-    ASSERT(isMainThread());
-    ASSERT(m_testUpdatesOnly);
-    setWebConnectionImpl(type, maxBandwidthMbps);
+    DCHECK(isMainThread());
+
+    {
+        MutexLocker locker(m_mutex);
+        m_hasOverride = false;
+    }
+
+    notifyObservers();
+    Page::networkStateChanged(onLine());

[jkarlin, 2016/06/24 14:47:50]

setOnline and setWebConnection check if anything has actually changed before
sending out notification. This should as well.

 }
 
-void NetworkStateNotifier::setWebConnectionImpl(WebConnectionType type, double maxBandwidthMbps)
+void NetworkStateNotifier::notifyObservers()
 {
     ASSERT(isMainThread());
+    WebConnectionType type = connectionType();
+    double maxBandwidthMbps = maxBandwidth();
 
     MutexLocker locker(m_mutex);
-    m_initialized = true;
-
-    if (m_type == type && m_maxBandwidthMbps == maxBandwidthMbps)
-        return;
-    m_type = type;
-    m_maxBandwidthMbps = maxBandwidthMbps;
-
     for (const auto& entry : m_observers) {
         ExecutionContext* context = entry.key;
         context->postTask(BLINK_FROM_HERE, createCrossThreadTask(&NetworkStateNotifier::notifyObserversOfConnectionChangeOnContext, crossThreadUnretained(this), type, maxBandwidthMbps));