[Android WebView] Implement support for Network Information API and enable it.

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index a710d513896e2f65cc45be90c0a0c6231c552b5f..7ec965fc3d99361dcb6e23176503ebc399a93f3e 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -69,6 +69,7 @@ import org.chromium.content_public.browser.navigation_controller.LoadURLType;
 import org.chromium.content_public.browser.navigation_controller.UserAgentOverrideOption;
 import org.chromium.content_public.common.Referrer;
 import org.chromium.net.NetError;
+import org.chromium.net.NetworkChangeNotifier;
 import org.chromium.ui.base.ActivityWindowAndroid;
 import org.chromium.ui.base.PageTransition;
 import org.chromium.ui.base.WindowAndroid;
@@ -2536,7 +2537,13 @@ public class AwContents implements SmartClipProvider,
 
     public void setNetworkAvailable(boolean networkUp) {
         if (TRACE) Log.d(TAG, "setNetworkAvailable=%s", networkUp);
-        if (!isDestroyed(WARN)) nativeSetJsOnlineProperty(mNativeAwContents, networkUp);
+        if (!isDestroyed(WARN)) {
+            // For backward compatibility when an app uses this API disable the
+            // Network Information API to prevent inconsistencies,
+            // see crbug.com/520088.
+            NetworkChangeNotifier.setAutoDetectConnectivityState(false);
+            nativeSetJsOnlineProperty(mNativeAwContents, networkUp);
+        }
     }
 
     /**