Refactor the overflow scroll fix.

Hope this is more understandable.

issue: 4203823
Change-Id: Ib1d95f6b250baf4b94f706e090a9f087aa9b7ed8

1 files changed, 10 insertions, 7 deletions

diff --git a/Source/WebCore/rendering/RenderLayer.cpp b/Source/WebCore/rendering/RenderLayer.cpp
index 0eae838..4e1c875 100644
--- a/Source/WebCore/rendering/RenderLayer.cpp
+++ b/Source/WebCore/rendering/RenderLayer.cpp
@@ -2274,13 +2274,16 @@ void RenderLayer::updateScrollInfoAfterLayout()
         updateOverflowStatus(horizontalOverflow, verticalOverflow);
 
 #if ENABLE(ANDROID_OVERFLOW_SCROLL)
-    bool hasOverflowScroll = ((horizontalOverflow && m_hBar) || (verticalOverflow && m_vBar)) &&
-            ((!renderer()->isTextArea() && !renderer()->isRenderBlock()) ||
-             // Disable customized overflow scroll for positioned RenderBlock.
-             (renderer()->isRenderBlock() && !renderer()->isPositioned()) ||
-             // Disable UI side scrolling for textareas, unless they are readonly.
-             (renderer()->isTextArea() && renderer()->node() &&
-              static_cast<HTMLTextAreaElement*>(renderer()->node())->readOnly()));
+    bool hasOverflowScroll = ((horizontalOverflow && m_hBar) || (verticalOverflow && m_vBar));
+    if (hasOverflowScroll) {
+        // Disable Android overflow scroll for positioned RenderBlock.
+        if (renderer()->isRenderBlock() && renderer()->isPositioned())
+            hasOverflowScroll = false;
+        // Disable UI side scrolling for non-readonly textareas.
+        else if (renderer()->isTextArea() && (!renderer()->node()
+                || !static_cast<HTMLTextAreaElement*>(renderer()->node())->readOnly()))
+            hasOverflowScroll = false;
+    }
     if (hasOverflowScroll != m_hasOverflowScroll) {
         m_hasOverflowScroll = hasOverflowScroll;
         dirtyZOrderLists();