* First bottom sheet commit
* Add empty files of needed classes
* Do animation using presentation controller and transitioning delegate
* Implement bottom sheet transition using just a UIPresentationController
* Tap background to dismiss
* Clean up and document bottom sheet interface
* Minor cleanup
* Fix usePreferredHeight
* Toggle usePreferredHeight
* Let UIPresentationController layout sheet view
* Expand bottom sheet delegate api
* Remove automaticallyDismissBottomSheet and usePreferredHeight
* Remove shouldDismiss
* Delegate method docs
* Allow custom bottom sheet widths
* Animate sheet view to new frame when rotating bottom sheet
* Fix sheet view starting in bad location
* Specify float for background color
* Clean up bottom sheet presentation controller
* Minor cleanup
* Copy cl/148818444
* GOO -> MDC
* s/draging/dragging/
* Use init instead of initWithCoder
* Bottom sheet example description
* Big improvements to bottom sheet examples
* MDCBottomSheetTransitionController
* Wrap up everything in MDCBottomSheetViewController
* Move all examples to MDCBottomSheetViewController
* Move supplemental code to BottomSheetSupplemental
* bottomSheetPresentationControllerDidDismissBottomSheet
* Check delegate implements methods before calling
* MDCBottomSheetViewController -> MDCBottomSheetController
* Add comments for MDCBottomSheetController
* Use MDCMath
* Change style of preferredContentSize setter
* Support preferredContentSize.height
* Add an example layed out using Autolayout
* More correctly set frame for non scrolling content
* Minor improvements to examples
* Small fixes for examples
* Use umbrella import headers
* Show custom preferredContentSize width in example
* MDCBottomSheetTransitionController now vends a presentation controller
* Expose bottom sheet presentation controller on UIViewController
* Final review comments
