Clarify fullscreenElement vs. currentFullScreenElement distinction

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

Index: third_party/WebKit/Source/web/tests/WebFrameTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
index f8575238dffc8609c72006c437bb057a9ce49f2c..f1bbff681bdedb1edde006f2967a0220397d2b9c 100644
--- a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
+++ b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
@@ -6458,7 +6458,7 @@ TEST_P(ParameterizedWebFrameTest, FullscreenLayerSize)
     Fullscreen::from(*document).requestFullscreen(*divFullscreen, Fullscreen::PrefixedRequest);
     webViewImpl->didEnterFullscreen();
     webViewImpl->updateAllLifecyclePhases();
-    ASSERT_TRUE(Fullscreen::isFullScreen(*document));
+    EXPECT_EQ(Fullscreen::currentFullScreenElementFrom(*document), divFullscreen);
 
     // Verify that the element is sized to the viewport.
     LayoutFullScreen* fullscreenLayoutObject = Fullscreen::from(*document).fullScreenLayoutObject();
@@ -6493,7 +6493,7 @@ TEST_F(WebFrameTest, FullscreenLayerNonScrollable)
     webViewImpl->updateAllLifecyclePhases();
 
     // Verify that the viewports are nonscrollable.
-    ASSERT_TRUE(Fullscreen::isFullScreen(*document));
+    EXPECT_EQ(Fullscreen::currentFullScreenElementFrom(*document), divFullscreen);
     FrameView* frameView = webViewHelper.webView()->mainFrameImpl()->frameView();
     WebLayer* layoutViewportScrollLayer = webViewImpl->compositor()->scrollLayer()->platformLayer();
     WebLayer* visualViewportScrollLayer = frameView->page()->frameHost().visualViewport().scrollLayer()->platformLayer();
@@ -6505,7 +6505,7 @@ TEST_F(WebFrameTest, FullscreenLayerNonScrollable)
     // Verify that the viewports are scrollable upon exiting fullscreen.
     webViewImpl->didExitFullscreen();
     webViewImpl->updateAllLifecyclePhases();
-    ASSERT_FALSE(Fullscreen::isFullScreen(*document));
+    EXPECT_EQ(Fullscreen::currentFullScreenElementFrom(*document), nullptr);
     ASSERT_TRUE(layoutViewportScrollLayer->userScrollableHorizontal());
     ASSERT_TRUE(layoutViewportScrollLayer->userScrollableVertical());
     ASSERT_TRUE(visualViewportScrollLayer->userScrollableHorizontal());
@@ -6530,7 +6530,7 @@ TEST_P(ParameterizedWebFrameTest, FullscreenMainFrame)
     webViewImpl->updateAllLifecyclePhases();
 
     // Verify that the main frame is still scrollable.
-    ASSERT_TRUE(Fullscreen::isFullScreen(*document));
+    EXPECT_EQ(Fullscreen::currentFullScreenElementFrom(*document), document->documentElement());
     WebLayer* webScrollLayer = webViewImpl->compositor()->scrollLayer()->platformLayer();
     ASSERT_TRUE(webScrollLayer->scrollable());
     ASSERT_TRUE(webScrollLayer->userScrollableHorizontal());