[repaint-after-layout] Skip invalidations if our RenderView did a full invalidation.

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index 8ec58d08914a74881c9cdea69332274fb6a15fda..d9aeb1a14fa659e33eb1bccf21689b957696c6fd 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -999,9 +999,6 @@ void FrameView::layout(bool allowSubtree)
         return;
 
     if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled()) {
-        if (m_doFullRepaint)
-            renderView()->setShouldDoFullRepaintAfterLayout(true);
-
         repaintTree(rootForThisLayout);
 
     } else if (m_doFullRepaint) {
@@ -1044,10 +1041,21 @@ void FrameView::repaintTree(RenderObject* root)
     // Until those states are fully fledged, I'll just disable the ASSERTS.
     DisableCompositingQueryAsserts disabler;
 
-    for (RenderObject* renderer = root; renderer; renderer = renderer->nextInPreOrder()) {
-        const LayoutRect& oldRepaintRect = renderer->oldRepaintRect();
-        const LayoutRect& newRepaintRect = renderer->newRepaintRect();
+    // If we are set to do a full repaint that means the RenderView will be
+    // invalidated. We can then skip issuing of invalidations for the child
+    // renderers as they'll be covered by the RenderView.
+    if (m_doFullRepaint) {
+        RenderObject* view = renderView();

[Julien - ping for review, 2014/03/31 20:28:35]

RenderView* view = renderView()!!!

[dsinclair, 2014/03/31 20:53:52]

Done.

+        view->repaintAfterLayoutIfNeeded(view->containerForRepaint(), true, view->oldRepaintRect(), &(view->newRepaintRect()));
 
+        // Clear the invalidation flags for the render view and child renderers.
+        for (RenderObject* renderer = view; renderer; renderer = renderer->nextInPreOrder()) {

[Julien - ping for review, 2014/03/31 20:28:35]

Shouldn't this be done on the |root|-rooted subtree and not the whole render
tree? (which would eliminate the need for |view|)

[dsinclair, 2014/03/31 20:53:52]

Done. Keeping view as it's used 4 times on the repaintAfterLayoutIfNeeded call.

+            renderer->clearRepaintState();
+        }
+        return;
+    }
+

[Julien - ping for review, 2014/03/31 20:28:35]

How about adding an ASSERT here that we don't need m_doFullRepaint as it would
mean unneeded invalidations?

[dsinclair, 2014/03/31 20:53:52]

Done.

+    for (RenderObject* renderer = root; renderer; renderer = renderer->nextInPreOrder()) {
         if ((renderer->onlyNeededPositionedMovementLayout() && renderer->compositingState() != PaintsIntoOwnBacking)
             || (renderer->shouldDoFullRepaintIfSelfPaintingLayer()
                 && renderer->hasLayer()
@@ -1067,7 +1075,7 @@ void FrameView::repaintTree(RenderObject* root)
 
         } else {
             didFullRepaint = renderer->repaintAfterLayoutIfNeeded(renderer->containerForRepaint(),
-                renderer->shouldDoFullRepaintAfterLayout(), oldRepaintRect, &newRepaintRect);
+                renderer->shouldDoFullRepaintAfterLayout(), renderer->oldRepaintRect(), &(renderer->newRepaintRect()));
         }
 
         if (!didFullRepaint)