[Devtools] Added test for negative lookaheads in network panel

third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html

Index: third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html b/third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html
index 24f30ec939b876158cf562c553ad6217a8535d87..a7c25f2e402f06aa8b0bdb0e7b2f405325ed2743 100644
--- a/third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html
+++ b/third_party/WebKit/LayoutTests/http/tests/inspector/network/network-filters.html
@@ -7,10 +7,11 @@ function test()
 {
     InspectorTest.recordNetwork();
 
-    var totalResourceCount = 3;
+    var totalResourceCount = 4;
     InspectorTest.makeFetch("resources/style.css", {}, ensureAllResources);
     InspectorTest.makeFetch("resources/abe.png", {}, ensureAllResources);
     InspectorTest.makeFetch("resources/abe.png", {}, ensureAllResources);
+    InspectorTest.makeFetch("missing/foo.bar", {}, ensureAllResources);
     var filterChecks = [{
         filterText: "-.css",
         isRegex: false
@@ -41,6 +42,9 @@ function test()
     }, {
         filterText: "png",
         isRegex: false
+    }, {
+        filterText: "-missing",
+        isRegex: false
     }];
 
     var resourceCount = 0;