Remove useless code to invalidate rects on the HostWindow. It's a no-op for frames.

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 4784dd7466c71d63bfc859a221047804fdb73f04..babd33585aaa68efb3b94fd53a3f83f02257ec9e 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -373,12 +373,6 @@ bool FrameView::didFirstLayout() const
 
 void FrameView::invalidateRect(const IntRect& rect)
 {
-    if (!parent()) {
-        if (HostWindow* window = getHostWindow())
-            window->invalidateRect(rect);
-        return;
-    }
-
     LayoutPartItem layoutItem = m_frame->ownerLayoutItem();
     if (layoutItem.isNull())
         return;