Do not size PermissionSelectorRow to preferred size

PermissionSelectorRow's preferred size is smaller than the width of the Page
Info Bubble, so when a permission changes, resizing to the preferred size means
that the row shrinks smaller than the other rows and the dropdown jumps around.

Instead, simply call Layout() to do a fresh layout of the row.

The parent()->SizeToPreferredSize() call is no longer necessary because
WebsiteSettingsPopupView calls SizeToContents() when a permission is
changed. Note that bug 655880 may want to reintroduce the
PermissionSelectorRow::ChildPreferredSizeChanged override and propagate the
change to WebsiteSettingsPopupView that way instead of via OnPermissionChanged,
but it's not needed now -- and I'm guessing that, for that bug,
PermissionSelectorRow::ChildPreferredSizeChanged may want to call
parent()->PreferredSizeChanged(), rather than calling SizeToPreferredSize()
(which assumes that the parent ought to be at its preferred size).

BUG=657286
TEST=On Windows/Linux, visit https://google.com (or any other site) and open
Page Info by clicking on the security indicator in the omnibox. Change a
permission, change it again. Observe that the dropdown does not jump to the left
of where it started.

Review-Url: https://codereview.chromium.org/2647633002
Cr-Commit-Position: refs/heads/master@{#445017}

chrome/browser/ui/views/website_settings/permission_selector_row.cc

@@ -293,12 +293,7 @@ void PermissionSelectorRow::AddObserver(
 }
 
 void PermissionSelectorRow::ChildPreferredSizeChanged(View* child) {
-  SizeToPreferredSize();
-  // FIXME: The parent is only a plain |View| that is used as a
-  // container/box/panel. The SizeToPreferredSize method of the parent is
-  // called here directly in order not to implement a custom |View| class with
-  // its own implementation of the ChildPreferredSizeChanged method.
-  parent()->SizeToPreferredSize();
+  Layout();
 }
 
 PermissionSelectorRow::~PermissionSelectorRow() {