Remove frame flattening support as Chromium has no intention of using it

Source/WebCore/page/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 460 matching lines @@
     // make it update the rendering area when set
     m_margins.setWidth(w);
 }
 
 void FrameView::setMarginHeight(LayoutUnit h)
 {
     // make it update the rendering area when set
     m_margins.setHeight(h);
 }
 
-bool FrameView::avoidScrollbarCreation() const
-{
-    ASSERT(m_frame);
-
-    // with frame flattening no subframe can have scrollbars
-    // but we also cannot turn scrollbars off as we determine
-    // our flattening policy using that.
-
-    if (!m_frame->ownerElement())
-        return false;
-
-    if (!m_frame->settings() || m_frame->settings()->frameFlatteningEnabled())
-        return true;
-
-    return false;
-}
-
 void FrameView::setCanHaveScrollbars(bool canHaveScrollbars)
 {
     m_canHaveScrollbars = canHaveScrollbars;
     ScrollView::setCanHaveScrollbars(canHaveScrollbars);
 }
 
 void FrameView::updateCanHaveScrollbars()
 {
     ScrollbarMode hMode;
     ScrollbarMode vMode;
@@ skipping 168 matching lines @@
         hMode = ScrollbarAuto;
         // Seamless documents begin with heights of 0; we special case that here
         // to correctly render documents that don't need scrollbars.
         IntSize fullVisibleSize = visibleContentRect(IncludeScrollbars).size();
         bool isSeamlessDocument = frame() && frame()->document() && frame()->document()->shouldDisplaySeamlesslyWithParent();
         vMode = (isSeamlessDocument && !fullVisibleSize.height()) ? ScrollbarAlwaysOff : ScrollbarAuto;
     } else {
         hMode = ScrollbarAlwaysOff;
         vMode = ScrollbarAlwaysOff;
     }
-    
+
     if (!m_layoutRoot) {
         Document* document = m_frame->document();
         Node* documentElement = document->documentElement();
         RenderObject* rootRenderer = documentElement ? documentElement->renderer() : 0;
         Node* body = document->body();
         if (body && body->renderer()) {
-            if (body->hasTagName(framesetTag) && m_frame->settings() && !m_frame->settings()->frameFlatteningEnabled()) {
+            if (body->hasTagName(framesetTag)) {
                 vMode = ScrollbarAlwaysOff;
                 hMode = ScrollbarAlwaysOff;
             } else if (body->hasTagName(bodyTag)) {
                 // It's sufficient to just check the X overflow,
                 // since it's illegal to have visible in only one direction.
                 RenderObject* o = rootRenderer->style()->overflowX() == OVISIBLE && document->documentElement()->hasTagName(htmlTag) ? body->renderer() : rootRenderer;
                 applyOverflowToViewport(o, hMode, vMode);
             }
         } else if (rootRenderer)
             applyOverflowToViewport(rootRenderer, hMode, vMode);
-    }    
+    }
 }
 
 void FrameView::updateCompositingLayersAfterStyleChange()
 {
     RenderView* renderView = this->renderView();
     if (!renderView)
         return;
 
     // If we expect to update compositing after an incipient layout, don't do so here.
     if (m_doingPreLayoutStyleUpdate || layoutPending() || renderView->needsLayout())
@@ skipping 220 matching lines @@
         return;
 
     TRACE_EVENT0("webkit", "FrameView::layout");
 
     // Protect the view from being deleted during layout (in recalcStyle)
     RefPtr<FrameView> protector(this);
 
     // Every scroll that happens during layout is programmatic.
     TemporaryChange<bool> changeInProgrammaticScroll(m_inProgrammaticScroll, true);
 
-    bool inChildFrameLayoutWithFrameFlattening = isInChildFrameWithFrameFlattening();
-
-    if (inChildFrameLayoutWithFrameFlattening) {
-        if (doLayoutWithFrameFlattening(allowSubtree))
-            return;
-    }
-
     m_layoutTimer.stop();
     m_delayedLayout = false;
     m_setNeedsLayoutWasDeferred = false;
 
     if (!m_frame) {
         // FIXME: Do we need to set m_size.width here?
         // FIXME: Should we set m_size.height here too?
         m_size.setWidth(layoutWidth());
         return;
     }
@@ skipping 13 matching lines @@
     ASSERT(m_frame->view() == this);
 
     Document* document = m_frame->document();
     ASSERT(!document->inPageCache());
     bool subtree;
     RenderObject* root;
 
     {
         TemporaryChange<bool> changeSchedulingEnabled(m_layoutSchedulingEnabled, false);
 
-        if (!m_nestedLayoutCount && !m_inSynchronousPostLayout && m_postLayoutTasksTimer.isActive() && !inChildFrameLayoutWithFrameFlattening) {
+        if (!m_nestedLayoutCount && !m_inSynchronousPostLayout && m_postLayoutTasksTimer.isActive()) {
             // This is a new top-level layout. If there are any remaining tasks from the previous
             // layout, finish them now.
             m_inSynchronousPostLayout = true;
             performPostLayoutTasks();
             m_inSynchronousPostLayout = false;
         }
 
         // Viewport-dependent media queries may cause us to need completely different style information.
         // Check that here.
         if (document->styleResolver()->affectedByViewportChange()) {
@@ skipping 31 matching lines @@
     RenderLayer* layer;
     {
         TemporaryChange<bool> changeSchedulingEnabled(m_layoutSchedulingEnabled, false);
 
         m_nestedLayoutCount++;
 
         if (!m_layoutRoot) {
             Document* document = m_frame->document();
             Node* body = document->body();
             if (body && body->renderer()) {
-                if (body->hasTagName(framesetTag) && m_frame->settings() && !m_frame->settings()->frameFlatteningEnabled()) {
+                if (body->hasTagName(framesetTag)) {
                     body->renderer()->setChildNeedsLayout(true);
                 } else if (body->hasTagName(bodyTag)) {
                     if (!m_firstLayout && m_size.height() != layoutHeight() && body->renderer()->enclosingBox()->stretchesToViewport())
                         body->renderer()->setChildNeedsLayout(true);
                 }
             }
 
 #ifdef INSTRUMENT_LAYOUT_SCHEDULING
             if (m_firstLayout && !m_frame->ownerElement())
                 printf("Elapsed time before first layout: %d\n", document->elapsedTime());
@@ skipping 111 matching lines @@
     ASSERT(!root->needsLayout());
 
     updateCanBlitOnScrollRecursively();
 
     if (document->hasListenerType(Document::OVERFLOWCHANGED_LISTENER))
         updateOverflowStatus(layoutWidth() < contentsWidth(),
                              layoutHeight() < contentsHeight());
 
     if (!m_postLayoutTasksTimer.isActive()) {
         if (!m_inSynchronousPostLayout) {
-            if (inChildFrameLayoutWithFrameFlattening) {
-                if (RenderView* renderView = this->renderView())
-                    renderView->updateWidgetPositions();
-            } else {
-                m_inSynchronousPostLayout = true;
-                // Calls resumeScheduledEvents()
-                performPostLayoutTasks();
-                m_inSynchronousPostLayout = false;
-            }
+            m_inSynchronousPostLayout = true;
+            // Calls resumeScheduledEvents()
+            performPostLayoutTasks();
+            m_inSynchronousPostLayout = false;
         }
-        
-        if (!m_postLayoutTasksTimer.isActive() && (needsLayout() || m_inSynchronousPostLayout || inChildFrameLayoutWithFrameFlattening)) {
-            // If we need layout or are already in a synchronous call to postLayoutTasks(), 
+
+        if (!m_postLayoutTasksTimer.isActive() && (needsLayout() || m_inSynchronousPostLayout)) {
+            // If we need layout or are already in a synchronous call to postLayoutTasks(),
             // defer widget updates and event dispatch until after we return. postLayoutTasks()
             // can make us need to update again, and we can get stuck in a nasty cycle unless
             // we call it through the timer here.
             m_postLayoutTasksTimer.startOneShot(0);
             if (needsLayout()) {
                 m_actionScheduler->pause();
                 layout();
             }
         }
     } else {
@@ skipping 831 matching lines @@
         m_layoutRoot->markContainingBlocksForLayout(false);
         m_layoutRoot = 0;
     }
     if (!m_layoutSchedulingEnabled)
         return;
     if (!needsLayout())
         return;
     if (!m_frame->document()->shouldScheduleLayout())
         return;
     InspectorInstrumentation::didInvalidateLayout(m_frame.get());
-    // When frame flattening is enabled, the contents of the frame could affect the layout of the parent frames.
-    // Also invalidate parent frame starting from the owner element of this frame.
-    if (m_frame->ownerRenderer() && isInChildFrameWithFrameFlattening())

[ojan, 2013/04/16 19:41:09]

This looks to be the only functional difference between this patch and Mike's.

-        m_frame->ownerRenderer()->setNeedsLayout(true, MarkContainingBlockChain);
 
     int delay = m_frame->document()->minimumLayoutDelay();
     if (m_layoutTimer.isActive() && m_delayedLayout && !delay)
         unscheduleRelayout();
     if (m_layoutTimer.isActive())
         return;
 
     m_delayedLayout = delay != 0;
 
 #ifdef INSTRUMENT_LAYOUT_SCHEDULING
@@ skipping 913 matching lines @@
 {
     if (!parent())
         return 0;
 
     if (Frame* parentFrame = m_frame->tree()->parent())
         return parentFrame->view();
 
     return 0;
 }
 
-bool FrameView::isInChildFrameWithFrameFlattening() const
-{
-    if (!parent() || !m_frame->ownerElement())
-        return false;
-
-    // Frame flattening applies when the owner element is either in a frameset or
-    // an iframe with flattening parameters.
-    if (m_frame->ownerElement()->hasTagName(iframeTag)) {
-        RenderIFrame* iframeRenderer = toRenderIFrame(m_frame->ownerElement()->renderPart());
-        if (iframeRenderer->flattenFrame() || iframeRenderer->isSeamless())
-            return true;
-    }
-
-    if (!m_frame->settings() || !m_frame->settings()->frameFlatteningEnabled())
-        return false;
-
-    if (m_frame->ownerElement()->hasTagName(frameTag))
-        return true;
-
-    return false;
-}
-
-bool FrameView::doLayoutWithFrameFlattening(bool allowSubtree)
-{
-    // Try initiating layout from the topmost parent.
-    FrameView* parentView = parentFrameView();
-
-    if (!parentView)
-        return false;
-
-    // In the middle of parent layout, no need to restart from topmost.
-    if (parentView->m_nestedLayoutCount)
-        return false;
-
-    // Parent tree is clean. Starting layout from it would have no effect.
-    if (!parentView->needsLayout())
-        return false;
-
-    while (parentView->parentFrameView())
-        parentView = parentView->parentFrameView();
-
-    parentView->layout(allowSubtree);
-
-    RenderObject* root = m_layoutRoot ? m_layoutRoot : m_frame->document()->renderer();
-    ASSERT_UNUSED(root, !root->needsLayout());
-
-    return true;
-}
-
 void FrameView::updateControlTints()
 {
     // This is called when control tints are changed from aqua/graphite to clear and vice versa.
     // We do a "fake" paint, and when the theme gets a paint call, it can then do an invalidate.
     // This is only done if the theme supports control tinting. It's up to the theme and platform
     // to define when controls get the tint and to call this function when that changes.
     
     // Optimize the common case where we bring a window to the front while it's still empty.
     if (!m_frame || m_frame->document()->url().isEmpty())
         return;
@@ skipping 181 matching lines @@
     Vector<RefPtr<FrameView> > frameViews;
     collectFrameViewChildren(this, frameViews);
 
     const Vector<RefPtr<FrameView> >::iterator end = frameViews.end();
     for (Vector<RefPtr<FrameView> >::iterator it = frameViews.begin(); it != end; ++it)
         (*it)->updateLayoutAndStyleIfNeededRecursive();
 
     // updateLayoutAndStyleIfNeededRecursive is called when we need to make sure style and layout are up-to-date before
     // painting, so we need to flush out any deferred repaints too.
     flushDeferredRepaints();
-
-    // When frame flattening is on, child frame can mark parent frame dirty. In such case, child frame

[ojan, 2013/04/16 19:41:09]

Also, Mike's patch leaves in this assert for seamless.

-    // needs to call layout on parent frame recursively.
-    // This assert ensures that parent frames are clean, when child frames finished updating layout and style.
-    ASSERT(!needsLayout());
 }
 
 void FrameView::enableAutoSizeMode(bool enable, const IntSize& minSize, const IntSize& maxSize)
 {
     ASSERT(!enable || !minSize.isEmpty());
     ASSERT(minSize.width() <= maxSize.width());
     ASSERT(minSize.height() <= maxSize.height());
 
     if (m_shouldAutoSize == enable && m_minAutoSize == minSize && m_maxAutoSize == maxSize)
         return;
@@ skipping 358 matching lines @@
 }
     
 AXObjectCache* FrameView::axObjectCache() const
 {
     if (frame() && frame()->document())
         return frame()->document()->existingAXObjectCache();
     return 0;
 }
     
 } // namespace WebCore