Detect change on video/viewport intersection when rendered remotely

third_party/WebKit/Source/web/tests/MediaElementFillingViewportTest.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/Document.h"
 #include "core/html/HTMLMediaElement.h"
 #include "platform/testing/UnitTestHelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "web/tests/sim/SimCompositor.h"
 #include "web/tests/sim/SimDisplayItemList.h"
 #include "web/tests/sim/SimRequest.h"
 #include "web/tests/sim/SimTest.h"
 
 namespace blink {
 
 class MediaElementFillingViewportTest : public SimTest {
  protected:
   MediaElementFillingViewportTest() { webView().resize(WebSize(640, 480)); }
 
   bool isMostlyFillingViewport(HTMLMediaElement* element) {
     return element->m_mostlyFillingViewport;
   }
 
   bool viewportFillDebouncerTimerActive(HTMLMediaElement* element) {
     return element->m_viewportFillDebouncerTimer.isActive();
   }
 
   void checkViewportIntersectionChanged(HTMLMediaElement* element) {
-    element->checkViewportIntersectionChanged();
+    element->activateViewportIntersectionMonitoring(true);
+    EXPECT_TRUE(element->m_checkViewportIntersectionTimer.isActive());
+    // TODO(xjz): Mock the time and wait for 1s instead.
+    element->checkViewportIntersectionTimerFired(nullptr);
   }
 
   std::unique_ptr<SimRequest> createMainResource() {
     std::unique_ptr<SimRequest> mainResource =
         WTF::wrapUnique(new SimRequest("https://example.com/", "text/html"));
     loadURL("https://example.com");
     return mainResource;
   }
 };
 
@@ skipping 104 matching lines @@
   element->setAttribute(
       "style", "position:fixed; left:0; top:240px; width:100%; height:100%;",
       ASSERT_NO_EXCEPTION);
   compositor().beginFrame();
   checkViewportIntersectionChanged(element);
   EXPECT_FALSE(isMostlyFillingViewport(element));
   EXPECT_FALSE(viewportFillDebouncerTimerActive(element));
 }
 
 }  // namespace blink