Reland of Use full viewport height for layout if URL bar is locked shown or hidden.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 97b239bca9e784930ef1cdd502f10efc62b75382..c91b67354a38fa03a4539263b7a1791a8176566d 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -1778,6 +1778,7 @@
   // viewport with the browser controls shown.
   IntSize ICBSize = m_size;
   if (RuntimeEnabledFeatures::inertTopControlsEnabled() &&
+      browserControls().permittedState() == WebBrowserControlsBoth &&
       !browserControls().shrinkViewport())
     ICBSize.expand(0, -browserControls().height());
 
@@ -1799,7 +1800,19 @@
 void WebViewImpl::updateBrowserControlsState(WebBrowserControlsState constraint,
                                              WebBrowserControlsState current,
                                              bool animate) {
+  WebBrowserControlsState oldPermittedState =
+      browserControls().permittedState();
+
   browserControls().updateConstraintsAndState(constraint, current, animate);
+
+  // If the controls are going from a locked to an unlocked state, or
+  // vice-versa, then we need to force a recompute of the ICB size since that
+  // depends on the permitted browser controls state.
+  if (oldPermittedState != constraint &&
+      (oldPermittedState == WebBrowserControlsBoth ||
+       constraint == WebBrowserControlsBoth)) {
+    performResize();
+  }
 
   if (m_layerTreeView)
     m_layerTreeView->updateBrowserControlsState(constraint, current, animate);
@@ -1847,8 +1860,7 @@
   return page()->frameHost().browserControls();
 }
 
-void WebViewImpl::resizeViewWhileAnchored(FrameView* view,
-                                          float browserControlsHeight,
+void WebViewImpl::resizeViewWhileAnchored(float browserControlsHeight,
                                           bool browserControlsShrinkLayout) {
   DCHECK(mainFrameImpl());
 
@@ -1912,12 +1924,10 @@
   if (isRotation) {
     RotationViewportAnchor anchor(*view, visualViewport, viewportAnchorCoords,
                                   pageScaleConstraintsSet());
-    resizeViewWhileAnchored(view, browserControlsHeight,
-                            browserControlsShrinkLayout);
+    resizeViewWhileAnchored(browserControlsHeight, browserControlsShrinkLayout);
   } else {
     ResizeViewportAnchor::ResizeScope resizeScope(*m_resizeViewportAnchor);
-    resizeViewWhileAnchored(view, browserControlsHeight,
-                            browserControlsShrinkLayout);
+    resizeViewWhileAnchored(browserControlsHeight, browserControlsShrinkLayout);
   }
   sendResizeEventAndRepaint();
 }