[Extensions Bindings] Notify of event unregistration on invalidation

extensions/renderer/api_event_handler_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/renderer/api_event_handler.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/test/mock_callback.h"
@@ skipping 689 matching lines @@
     v8::Local<v8::Function> listener =
         FunctionFromString(context_b, "(function() {})");
     v8::Local<v8::Value> argv[] = {event1_b, listener};
     RunFunction(add_listener, context_b, arraysize(argv), argv);
     ::testing::Mock::VerifyAndClearExpectations(&change_handler);
   }
   EXPECT_EQ(1u,
             handler.GetNumEventListenersForTesting(kEventName1, context_b));
 }
 
+// Tests that, when the context is invalidated, the listeners are removed.
+TEST_F(APIEventHandlerTest, TestContextInvalidation) {
+  v8::HandleScope handle_scope(isolate());
+  v8::Local<v8::Context> context = ContextLocal();
+
+  MockEventChangeHandler change_handler;
+  APIEventHandler handler(base::Bind(&RunFunctionOnGlobalAndIgnoreResult),
+                          change_handler.Get());
+
+  const char kEventName[] = "onFoo";
+  v8::Local<v8::Object> event =
+      handler.CreateEventInstance(kEventName, context);
+  const char kAddListenerFunction[] =
+      "(function(event, listener) { event.addListener(listener); })";
+
+  // Add a listener to the first event. The APIEventHandler should notify
+  // since it's a change in state (no listeners -> listeners).
+  v8::Local<v8::Function> add_listener =
+      FunctionFromString(context, kAddListenerFunction);
+  v8::Local<v8::Function> listener =
+      FunctionFromString(context, "(function() {})");
+
+  EXPECT_CALL(
+      change_handler,
+      Run(kEventName, binding::EventListenersChanged::HAS_LISTENERS, context))
+      .Times(1);
+  v8::Local<v8::Value> argv[] = {event, listener};
+  RunFunction(add_listener, context, arraysize(argv), argv);
+  ::testing::Mock::VerifyAndClearExpectations(&change_handler);
+  EXPECT_EQ(1u, handler.GetNumEventListenersForTesting(kEventName, context));
+
+  // When the contexts are invalidated, we should receive listener removed
+  // notifications.
+  EXPECT_CALL(
+      change_handler,
+      Run(kEventName, binding::EventListenersChanged::NO_LISTENERS, context))
+      .Times(1);
+  handler.InvalidateContext(context);
+  ::testing::Mock::VerifyAndClearExpectations(&change_handler);
+}
+
 }  // namespace extensions