IntersectionObserver: Always send an initial notification.

third_party/WebKit/Source/web/tests/IntersectionObserverTest.cpp

 // 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 "core/dom/IntersectionObserver.h"
 
 #include "core/dom/IntersectionObserverCallback.h"
 #include "core/dom/IntersectionObserverInit.h"
 #include "core/frame/FrameView.h"
 #include "platform/testing/UnitTestHelpers.h"
@@ skipping 73 matching lines @@
   IntersectionObserver* observer = IntersectionObserver::create(
       observerInit, *observerCallback, exceptionState);
   ASSERT_FALSE(exceptionState.hadException());
 
   Element* target = document().getElementById("target");
   ASSERT_TRUE(target);
   observer->observe(target, exceptionState);
 
   compositor().beginFrame();
   testing::runPendingTasks();
-  EXPECT_EQ(observerCallback->callCount(), 0);
+  EXPECT_EQ(observerCallback->callCount(), 1);
 
   // When document is not suspended, beginFrame() will generate notifications
   // and post a task to deliver them.
   document().view()->layoutViewportScrollableArea()->setScrollOffset(
       ScrollOffset(0, 300), ProgrammaticScroll);
   compositor().beginFrame();
-  EXPECT_EQ(observerCallback->callCount(), 0);
+  EXPECT_EQ(observerCallback->callCount(), 1);
   testing::runPendingTasks();
-  EXPECT_EQ(observerCallback->callCount(), 1);
+  EXPECT_EQ(observerCallback->callCount(), 2);
 
   // When a document is suspended, beginFrame() will generate a notification,
   // but it will not be delivered.  The notification will, however, be
   // available via takeRecords();
   document().suspendScheduledTasks();
   document().view()->layoutViewportScrollableArea()->setScrollOffset(
       ScrollOffset(0, 0), ProgrammaticScroll);
   compositor().beginFrame();
-  EXPECT_EQ(observerCallback->callCount(), 1);
+  EXPECT_EQ(observerCallback->callCount(), 2);
   testing::runPendingTasks();
-  EXPECT_EQ(observerCallback->callCount(), 1);
+  EXPECT_EQ(observerCallback->callCount(), 2);
   EXPECT_FALSE(observer->takeRecords(exceptionState).isEmpty());
 
   // Generate a notification while document is suspended; then resume document.
   // Notification should happen in a post task.
   document().view()->layoutViewportScrollableArea()->setScrollOffset(
       ScrollOffset(0, 300), ProgrammaticScroll);
   compositor().beginFrame();
   testing::runPendingTasks();
-  EXPECT_EQ(observerCallback->callCount(), 1);
+  EXPECT_EQ(observerCallback->callCount(), 2);
   document().resumeScheduledTasks();
-  EXPECT_EQ(observerCallback->callCount(), 1);
+  EXPECT_EQ(observerCallback->callCount(), 2);
   testing::runPendingTasks();
-  EXPECT_EQ(observerCallback->callCount(), 2);
+  EXPECT_EQ(observerCallback->callCount(), 3);
 }
 
 }  // namespace blink