Forward WM_NCHITTEST messages from the LegacyRenderWidgetHostHWND class to the parent window.

content/browser/renderer_host/legacy_render_widget_host_win.cc

Index: content/browser/renderer_host/legacy_render_widget_host_win.cc
diff --git a/content/browser/renderer_host/legacy_render_widget_host_win.cc b/content/browser/renderer_host/legacy_render_widget_host_win.cc
index f512c5d123a322b65b191cab01033fbbbe7fe886..61a28fe09b7e5be42cf38c353481a55609163620 100644
--- a/content/browser/renderer_host/legacy_render_widget_host_win.cc
+++ b/content/browser/renderer_host/legacy_render_widget_host_win.cc
@@ -155,9 +155,11 @@ LRESULT LegacyRenderWidgetHostHWND::OnMouseRange(UINT message,
     w_param = MAKEWPARAM(LOWORD(w_param), SPECIAL_MOUSEMOVE_NOT_TO_BE_TRACKED);
   }
 
-  // The offsets in mouse wheel messages are in screen coordinates. We should
-  // not be converting them to parent coordinates.
-  if (message != WM_MOUSEWHEEL && message != WM_MOUSEHWHEEL) {
+  // The offsets for WM_NCXXX and WM_MOUSEWHEEL and WM_MOUSEHWHEEL messages are
+  // in screen coordinates. We should not be converting them to parent
+  // coordinates.
+  if ((message >= WM_MOUSEFIRST && message <= WM_MOUSELAST) &&
+      (message != WM_MOUSEWHEEL && message != WM_MOUSEHWHEEL)) {
     POINT mouse_coords;
     mouse_coords.x = GET_X_LPARAM(l_param);
     mouse_coords.y = GET_Y_LPARAM(l_param);
@@ -210,6 +212,12 @@ LRESULT LegacyRenderWidgetHostHWND::OnScroll(UINT message,
   return ::SendMessage(GetParent(), message, w_param, l_param);
 }
 
+LRESULT LegacyRenderWidgetHostHWND::OnNCHitTest(UINT message,
+                                                WPARAM w_param,
+                                                LPARAM l_param) {
+  return ::SendMessage(GetParent(), message, w_param, l_param);
+}
+
 LRESULT LegacyRenderWidgetHostHWND::OnNCPaint(UINT message,
                                               WPARAM w_param,
                                               LPARAM l_param) {