Add a force-layout-height-to-zero layout mode to WebViewImpl

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 342 matching lines @@
     , m_spellCheckClient(0)
     , m_chromeClientImpl(this)
     , m_contextMenuClientImpl(this)
     , m_dragClientImpl(this)
     , m_editorClientImpl(this)
     , m_inspectorClientImpl(this)
     , m_backForwardClientImpl(this)
     , m_spellCheckerClientImpl(this)
     , m_storageClientImpl(this)
     , m_fixedLayoutSizeLock(false)
+    , m_forceZeroLayoutHeight(false)
     , m_shouldAutoResize(false)
     , m_zoomLevel(0)
     , m_minimumZoomLevel(zoomFactorToZoomLevel(minTextSizeMultiplier))
     , m_maximumZoomLevel(zoomFactorToZoomLevel(maxTextSizeMultiplier))
     , m_doubleTapZoomPageScaleFactor(0)
     , m_doubleTapZoomPending(false)
     , m_enableFakePageScaleAnimationForTesting(false)
     , m_fakePageScaleAnimationPageScaleFactor(0)
     , m_fakePageScaleAnimationUseAnchor(false)
     , m_contextMenuAllowed(false)
@@ skipping 2669 matching lines @@
     if (settings()->viewportEnabled()) {
         layoutSize = flooredIntSize(m_pageScaleConstraintsSet.pageDefinedConstraints().layoutSize);
 
         bool textAutosizingEnabled = page()->settings().textAutosizingEnabled();
         if (textAutosizingEnabled && layoutSize.width != view->layoutSize().width()) {
             if (TextAutosizer* textAutosizer = page()->deprecatedLocalMainFrame()->document()->textAutosizer())
                 textAutosizer->recalculateMultipliers();
         }
     }
 
+    if (m_forceZeroLayoutHeight)
+        layoutSize.height = 0;
+
     view->setLayoutSize(layoutSize);
 }
 
 IntSize WebViewImpl::contentsSize() const
 {
     if (!page()->mainFrame()->isLocalFrame())
         return IntSize();
     RenderView* root = page()->deprecatedLocalMainFrame()->contentRenderer();
     if (!root)
         return IntSize();
@@ skipping 37 matching lines @@
     // Clear out the values for the current history item. This will prevent the history item from clobbering the
     // value determined during page scale initialization, which may be less than 1.
     page()->deprecatedLocalMainFrame()->loader().clearScrollPositionAndViewState();
     m_pageScaleConstraintsSet.setNeedsReset(true);
 
     // Clobber saved scales and scroll offsets.
     if (FrameView* view = page()->deprecatedLocalMainFrame()->document()->view())
         view->cacheCurrentScrollPosition();
 }
 
+void WebViewImpl::setForceZeroLayoutHeight(bool enable)
+{
+    if (m_forceZeroLayoutHeight == enable)
+        return;
+
+    m_forceZeroLayoutHeight = enable;
+    updateMainFrameLayoutSize();
+}
+
 void WebViewImpl::setFixedLayoutSize(const WebSize& layoutSize)
 {
     if (!page() || !page()->mainFrame()->isLocalFrame())
         return;
 
     LocalFrame* frame = page()->deprecatedLocalMainFrame();
     if (!frame)
         return;
 
     RefPtr<FrameView> view = frame->view();
@@ skipping 1060 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink