aura: Use the default high-dpi cursor for unsupported cursors.

For cursors that don't have an aura-image asset, the corresponding
X11 cursor is displayed. However, in high-dpi, the default X11 cursors
are small. So always use the high-dpi default-cursor for these cases.

BUG=143268

Review URL: https://chromiumcodereview.appspot.com/10854211

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152341 0039d316-1c4b-4281-b951-d872f2087c98

ui/aura/root_window_host_linux.cc

@@ -1051,12 +1051,17 @@ bool RootWindowHostLinux::IsWindowManagerPresent() {
 }
 
 void RootWindowHostLinux::SetCursorInternal(gfx::NativeCursor cursor) {
-  ::Cursor xcursor =
-      image_cursors_->IsImageCursor(cursor) ?
-      image_cursors_->ImageCursorFromNative(cursor) :
-      (cursor == ui::kCursorNone ? invisible_cursor_ :
-       (cursor == ui::kCursorCustom ? cursor.platform() :
-        ui::GetXCursor(CursorShapeFromNative(cursor))));
+  ::Cursor xcursor;
+  if (image_cursors_->IsImageCursor(cursor))
+    xcursor = image_cursors_->ImageCursorFromNative(cursor);
+  else if (cursor == ui::kCursorNone)
+    xcursor =  invisible_cursor_;
+  else if (cursor == ui::kCursorCustom)
+    xcursor = cursor.platform();
+  else if (delegate_->GetDeviceScaleFactor() == 1.0)
+    xcursor = ui::GetXCursor(CursorShapeFromNative(cursor));
+  else
+    xcursor = image_cursors_->ImageCursorFromNative(ui::kCursorPointer);
   XDefineCursor(xdisplay_, xwindow_, xcursor);
 }