Expose scroll containers via accessibility APIs.

Source/modules/accessibility/AXObject.cpp

Index: Source/modules/accessibility/AXObject.cpp
diff --git a/Source/modules/accessibility/AXObject.cpp b/Source/modules/accessibility/AXObject.cpp
index 6c614bc316af40c592fb7ac80277f6d05df46665..11b3285c06ee5235122eecfe6d0eae4623becff4 100644
--- a/Source/modules/accessibility/AXObject.cpp
+++ b/Source/modules/accessibility/AXObject.cpp
@@ -1008,6 +1008,59 @@ const AtomicString& AXObject::getAttribute(const QualifiedName& attribute) const
     return element->fastGetAttribute(attribute);
 }
 
+//
+// Scrollable containers.
+//
+
+//
+// Scrollable containers.

[aboxhall, 2015/05/01 23:05:42]

Double comment?

+//
+
+bool AXObject::isScrollableContainer() const
+{
+    return !!getScrollableAreaIfScrollable();

[aboxhall, 2015/05/01 23:05:42]

Ugh, I don't like !! but it seems to be the de facto standard in blink code.

+}
+
+IntPoint AXObject::scrollOffset() const
+{
+    ScrollableArea* area = getScrollableAreaIfScrollable();
+    if (!area)
+        return IntPoint();
+
+    return IntPoint(area->scrollPosition().x(), area->scrollPosition().y());
+}
+
+IntPoint AXObject::minimumScrollOffset() const
+{
+    ScrollableArea* area = getScrollableAreaIfScrollable();
+    if (!area)
+        return IntPoint();
+
+    return IntPoint(area->minimumScrollPosition().x(), area->minimumScrollPosition().y());
+}
+
+IntPoint AXObject::maximumScrollOffset() const
+{
+    ScrollableArea* area = getScrollableAreaIfScrollable();
+    if (!area)
+        return IntPoint();
+
+    return IntPoint(area->maximumScrollPosition().x(), area->maximumScrollPosition().y());
+}
+
+void AXObject::setScrollOffset(const IntPoint& offset) const
+{
+    ScrollableArea* area = getScrollableAreaIfScrollable();
+    if (!area)
+        return;
+
+    area->setScrollPosition(DoublePoint(offset.x(), offset.y()));
+}
+
+//
+// Modify or take an action on an object.
+//
+
 bool AXObject::press() const
 {
     Element* actionElem = actionElement();
@@ -1145,7 +1198,7 @@ void AXObject::scrollToMakeVisibleWithSubFocus(const IntRect& subfocus) const
         objectRect.y(), objectRect.maxY(),
         0, scrollVisibleRect.height());
 
-    scrollParent->scrollTo(IntPoint(desiredX, desiredY));
+    scrollParent->setScrollOffset(IntPoint(desiredX, desiredY));
 
     // Convert the subfocus into the coordinates of the scroll parent.
     IntRect newSubfocus = subfocus;
@@ -1201,7 +1254,7 @@ void AXObject::scrollToGlobalPoint(const IntPoint& globalPoint) const
             objectRect.y(), objectRect.maxY(),
             objectRect.y(), objectRect.maxY(),
             point.y(), point.y());
-        outer->scrollTo(IntPoint(desiredX, desiredY));
+        outer->setScrollOffset(IntPoint(desiredX, desiredY));
 
         if (outer->isAXScrollView() && !inner->isAXScrollView()) {
             // If outer object we just scrolled is a scroll view (main window or iframe) but the