Don't change layout size due to top control show/hide

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

Index: third_party/WebKit/Source/web/tests/TopControlsTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/TopControlsTest.cpp b/third_party/WebKit/Source/web/tests/TopControlsTest.cpp
index c81cd278c74753bc76b7cdc33eafa6cd23ffdcee..26e5274aeb764d6a484c24986a6e304f7fac61e1 100644
--- a/third_party/WebKit/Source/web/tests/TopControlsTest.cpp
+++ b/third_party/WebKit/Source/web/tests/TopControlsTest.cpp
@@ -29,6 +29,7 @@
  */
 #include "core/frame/TopControls.h"
 
+#include "core/dom/ClientRect.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ -37,6 +38,7 @@
 #include "platform/testing/URLTestHelpers.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebUnitTestSupport.h"
+#include "public/web/WebElement.h"
 #include "public/web/WebSettings.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -57,6 +59,8 @@ public:
         registerMockedHttpURLLoad("overflow-scrolling.html");
         registerMockedHttpURLLoad("iframe-scrolling.html");
         registerMockedHttpURLLoad("iframe-scrolling-inner.html");
+        registerMockedHttpURLLoad("percent-height.html");
+        registerMockedHttpURLLoad("vh-height.html");
     }
 
     ~TopControlsTest() override
@@ -112,6 +116,13 @@ public:
         webViewImpl()->handleInputEvent(generateEvent(WebInputEvent::GestureScrollEnd));
     }
 
+    PassRefPtrWillBeRawPtr<Element> getElementById(const WebString& id)
+    {
+        return static_cast<PassRefPtrWillBeRawPtr<Element>>(
+            webViewImpl()->mainFrame()->document().getElementById(id));
+    }
+
+
     WebViewImpl* webViewImpl() const { return m_helper.webViewImpl(); }
     LocalFrame* frame() const { return m_helper.webViewImpl()->mainFrameImpl()->frame(); }
     VisualViewport& visualViewport() const { return m_helper.webViewImpl()->page()->frameHost().visualViewport(); }
@@ -544,4 +555,85 @@ TEST_F(TopControlsTest, MAYBE(StateConstraints))
     EXPECT_POINT_EQ(IntPoint(0, 90), frame()->view()->scrollPosition());
 }
 
+// Ensure that top controls do not affect the layout by showing and hiding
+// except for position: fixed elements.
+TEST_F(TopControlsTest, MAYBE(DontAffectLayoutHeight))
+{
+    // Initialize with the top controls showing.
+    WebViewImpl* webView = initialize("percent-height.html");
+    webView->setTopControlsHeight(100.f, true);
+    webView->updateTopControlsState(WebTopControlsBoth, WebTopControlsShown, false);
+    webView->topControls().setShownRatio(1);
+    webView->resize(WebSize(400, 300));
+    webView->updateAllLifecyclePhases();
+    EXPECT_FLOAT_EQ(100.f, webView->topControls().contentOffset());
+
+    // When the top controls are showing, there's 300px for the layout height so 50%
+    // should result in both the position:fixed and position: absolute divs having
+    // 150px of height.
+    RefPtrWillBeRawPtr<Element> absPos = getElementById(WebString::fromUTF8("abs"));
+    RefPtrWillBeRawPtr<Element> fixedPos = getElementById(WebString::fromUTF8("fixed"));
+    EXPECT_FLOAT_EQ(150.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(150.f, fixedPos->getBoundingClientRect()->height());
+
+    // The layout size on the FrameView should not include the top controls.
+    EXPECT_EQ(300, frame()->view()->layoutSize(IncludeScrollbars).height());
+
+    // Hide the top controls.
+    verticalScroll(-100.f);
+    EXPECT_FLOAT_EQ(0.f, webView->topControls().contentOffset());
+    EXPECT_POINT_EQ(IntPoint(0, 0), frame()->view()->scrollPosition());
+    webView->setTopControlsHeight(100.f, false);
+    webView->resize(WebSize(400, 400));
+    webView->updateAllLifecyclePhases();
+
+    // Hiding the top controls shouldn't change the height of the initial
+    // containing block for non-position: fixed. Position: fixed however should
+    // use the entire height of the viewport however.
+    EXPECT_FLOAT_EQ(150.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(200.f, fixedPos->getBoundingClientRect()->height());
+
+    // The layout size should not change as a result of top controls hiding.
+    EXPECT_EQ(300, frame()->view()->layoutSize(IncludeScrollbars).height());
+}
+
+// Ensure that top controls do not affect vh units.
+TEST_F(TopControlsTest, MAYBE(DontAffectVHUnits))
+{
+    // Initialize with the top controls showing.
+    WebViewImpl* webView = initialize("vh-height.html");
+    webView->setTopControlsHeight(100.f, true);
+    webView->updateTopControlsState(WebTopControlsBoth, WebTopControlsShown, false);
+    webView->topControls().setShownRatio(1);
+    webView->resize(WebSize(400, 300));
+    webView->updateAllLifecyclePhases();
+    EXPECT_FLOAT_EQ(100.f, webView->topControls().contentOffset());
+
+    // 'vh' units should be based on the viewport when the top controls are
+    // hidden.
+    RefPtrWillBeRawPtr<Element> absPos = getElementById(WebString::fromUTF8("abs"));
+    RefPtrWillBeRawPtr<Element> fixedPos = getElementById(WebString::fromUTF8("fixed"));
+    EXPECT_FLOAT_EQ(200.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(200.f, fixedPos->getBoundingClientRect()->height());
+
+    // The size used for viewport units should not be reduced by the top controls.
+    EXPECT_EQ(400, frame()->view()->viewportSizeForViewportUnits().height());
+
+    // Hide the top controls.
+    verticalScroll(-100.f);
+    EXPECT_FLOAT_EQ(0.f, webView->topControls().contentOffset());
+    EXPECT_POINT_EQ(IntPoint(0, 0), frame()->view()->scrollPosition());
+    webView->setTopControlsHeight(100.f, false);
+    webView->resize(WebSize(400, 400));
+    webView->updateAllLifecyclePhases();
+
+    // vh units should be static with respect to the top controls so neighter
+    // <div> should change size are a result of the top controls hiding.
+    EXPECT_FLOAT_EQ(200.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(200.f, fixedPos->getBoundingClientRect()->height());
+
+    // The viewport size used for vh units should not change as a result of top controls hiding.
+    EXPECT_EQ(400, frame()->view()->viewportSizeForViewportUnits().height());
+}
+
 } // namespace blink