am f69d55a8: am 635861a9: DO NOT MERGE:Fix position update

* commit 'f69d55a820e0b7b57af6a843880f5338a220b27c':
  DO NOT MERGE:Fix position update

2 files changed, 15 insertions, 18 deletions

diff --git a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
index 4198608..ea95d6a 100644
--- a/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
@@ -245,15 +245,14 @@ void GraphicsLayerAndroid::updateFixedPosition()
         marginRight = convertLength(view->style()->marginRight());
         marginBottom = convertLength(view->style()->marginBottom());
 
-        // The layer can be bigger than the element we want to draw;
-        // not only that, the layout rect of the element might also be
-        // different from the visible rect of that element (i.e. the element
-        // has a CSS shadow property -- the shadow is "outside" the element).
-        // We thus need to:
-        // 1/ get the size of the element (w,h), using the layoutOverflow rect
-        // 2/ pass the current offset of the painting relative to the layer
-        int w = view->rightLayoutOverflow() - view->leftLayoutOverflow();
-        int h = view->bottomLayoutOverflow() - view->topLayoutOverflow();
+        // In order to compute the fixed element's position, we need the width
+        // and height of the element when bottom or right is defined.
+        // And here we should use the non-overflowed value, that means, the
+        // overflowed content (e.g. outset shadow) will not be counted into the
+        // width and height.
+        int w = view->width();
+        int h = view->height();
+
         int paintingOffsetX = - offsetFromRenderer().width();
         int paintingOffsetY = - offsetFromRenderer().height();
 
diff --git a/WebCore/platform/graphics/android/LayerAndroid.cpp b/WebCore/platform/graphics/android/LayerAndroid.cpp
index bf60d3b..4e3f55d 100644
--- a/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -547,21 +547,19 @@ void LayerAndroid::updateFixedLayersPositions(SkRect viewport, LayerAndroid* par
         float x = dx;
         float y = dy;
 
-        // It turns out that when it is 'auto', the webkit computation will
-        // take one more factor into account,  that is the original render
-        // layer's X,Y, such that it will align well with the parent's layer.
+        // It turns out that when it is 'auto', we should use the webkit value
+        // from the original render layer's X,Y, that will take care of alignment
+        // with the parent's layer and fix Margin etc.
         if (!(m_fixedLeft.defined() || m_fixedRight.defined()))
             x += m_renderLayerPos.x();
-
-        if (!(m_fixedTop.defined() || m_fixedBottom.defined()))
-            y += m_renderLayerPos.y();
-
-        if (m_fixedLeft.defined() || !m_fixedRight.defined())
+        else if (m_fixedLeft.defined() || !m_fixedRight.defined())
             x += m_fixedMarginLeft.calcFloatValue(w) + m_fixedLeft.calcFloatValue(w) - m_fixedRect.fLeft;
         else
             x += w - m_fixedMarginRight.calcFloatValue(w) - m_fixedRight.calcFloatValue(w) - m_fixedRect.fRight;
 
-        if (m_fixedTop.defined() || !m_fixedBottom.defined())
+        if (!(m_fixedTop.defined() || m_fixedBottom.defined()))
+            y += m_renderLayerPos.y();
+        else if (m_fixedTop.defined() || !m_fixedBottom.defined())
             y += m_fixedMarginTop.calcFloatValue(h) + m_fixedTop.calcFloatValue(h) - m_fixedRect.fTop;
         else
             y += h - m_fixedMarginBottom.calcFloatValue(h) - m_fixedBottom.calcFloatValue(h) - m_fixedRect.fBottom;