[rAC] Allow sub-views to trigger layout reflow.

chrome/browser/ui/cocoa/autofill/autofill_layout.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_COCOA_AUTOFILL_AUTOFILL_LAYOUT_H_
+#define CHROME_BROWSER_UI_COCOA_AUTOFILL_AUTOFILL_LAYOUT_H_
+
+#import <Cocoa/Cocoa.h>
+
+// Defines a protocol that allows resizing a view hierarchy based on the size
+// requirements of the subviews. Is implemented by either views or view
+// controllers.
+// The way this works together is:
+// * Subview indicates by calling -requestRelayout on the window controller.
+// * Window controller queries subviews for preferredSize to determine the
+//   total size of the contentView, adjusts subview origins appropriately,
+//   and calls performLayout on each subview.
+// * Subviews then recursively do the same thing.
+@protocol AutofillLayout
+
+// Query the preferred size, without actually layouting.
+// Akin to -intrinsicContentSize on 10.7
+- (NSSize)preferredSize;
+
+// Layout the content according to the preferred size. Will not touch
+// frameOrigin. If all objects in the hierarchy were custom views (and not
+// view controllers), this could be replaced by overriding
+// -resizeSubviewsWithOldSize:.
+- (void)performLayout;
+
+@end
+
+#endif  // CHROME_BROWSER_UI_COCOA_AUTOFILL_AUTOFILL_LAYOUT_H_