vh units shouldn't add controls height when controls are locked to hidden.

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

 /*
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 987 matching lines @@
     visualViewport().clampToBoundaries();
     view->setScrollOffset(view->getScrollOffset(), ProgrammaticScroll);
 
     ASSERT_EQ(80.f, webView->browserControls().contentOffset());
     EXPECT_EQ(expectedRootOffset, rootViewport->getScrollOffset().height());
 
     webView->handleInputEvent(generateEvent(WebInputEvent::GestureScrollEnd));
   }
 }
 
+// Ensure that vh units are correct when browser controls are in a locked
+// state. That is, normally we need to add the browser controls height to vh
+// units since 100vh includes the browser controls even if they're hidden while
+// the ICB height does not. When the controls are locked hidden, the ICB size
+// is the full viewport height so there's no need to add the browser controls
+// height.  crbug.com/688738.
+TEST_F(BrowserControlsTest, MAYBE(ViewportUnitsWhenControlsLocked)) {
+  // Initialize with the browser controls showing.
+  WebViewImpl* webView = initialize("vh-height.html");
+  webView->resizeWithBrowserControls(WebSize(400, 300), 100.f, true);
+  webView->updateBrowserControlsState(WebBrowserControlsBoth,
+                                      WebBrowserControlsShown, false);
+  webView->browserControls().setShownRatio(1);
+  webView->updateAllLifecyclePhases();
+
+  ASSERT_EQ(100.f, webView->browserControls().contentOffset());
+  ASSERT_EQ(300, frame()->view()->layoutSize().height());
+
+  Element* absPos = getElementById(WebString::fromUTF8("abs"));
+  Element* fixedPos = getElementById(WebString::fromUTF8("fixed"));
+
+  // Lock the browser controls to hidden.
+  {
+    webView->updateBrowserControlsState(WebBrowserControlsHidden,
+                                        WebBrowserControlsHidden, false);
+    webView->resizeWithBrowserControls(WebSize(400, 400), 100.f, false);
+    webView->updateAllLifecyclePhases();
+
+    ASSERT_EQ(0.f, webView->browserControls().contentOffset());
+    ASSERT_EQ(400, frame()->view()->layoutSize().height());
+
+    // Make sure we're not adding the browser controls height to the vh units
+    // as when they're locked to hidden, the ICB fills the entire viewport
+    // already.
+    EXPECT_FLOAT_EQ(200.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(200.f, fixedPos->getBoundingClientRect()->height());
+    EXPECT_EQ(400, frame()->view()->viewportSizeForViewportUnits().height());
+  }
+
+  // Lock the browser controls to shown. This should cause the vh units to
+  // behave as usual by including the browser controls region in 100vh.
+  {
+    webView->updateBrowserControlsState(WebBrowserControlsShown,
+                                        WebBrowserControlsShown, false);
+    webView->resizeWithBrowserControls(WebSize(400, 300), 100.f, true);
+    webView->updateAllLifecyclePhases();
+
+    ASSERT_EQ(100.f, webView->browserControls().contentOffset());
+    ASSERT_EQ(300, frame()->view()->layoutSize().height());
+
+    // Make sure we're not adding the browser controls height to the vh units as
+    // when they're locked to hidden, the ICB fills the entire viewport already.
+    EXPECT_FLOAT_EQ(200.f, absPos->getBoundingClientRect()->height());
+    EXPECT_FLOAT_EQ(200.f, fixedPos->getBoundingClientRect()->height());
+    EXPECT_EQ(400, frame()->view()->viewportSizeForViewportUnits().height());
+  }
+}
+
 }  // namespace blink