This fixes a problem with reparenting of focus nodes where it would remove the node from the scope's focused children when reparented, even if it was being reparented to another place under the same scope. This only occurred if the scope in question didn't have focus.

This caused nodes to not get autofocused when they were a child of another node within the scope, and were reparented, and then the scope was given focus (as when a route is pushed).

This keeps the node in the scope's child list where it was if the node is reparented under a parent within the same scope.

- Added a test that tries to autofocus a TextField when the route is pushed and there is another 
  FocusNode above the text field. This was how this was first noticed: the autofocus got ignored in 
  this configuration.

- Added a test to focus_manager_test that tests for the specific case of reparenting a node when 
  it's in the focused children of the scope.

* Updated the BottomAppBar to use elevation overlays when a dark theme is used.

* Moved the code for calculating the overlay color to a new utility
ElevationOverlay class and made it private by not including in the material package.

* Allow showModalBottomSheet to present bottom sheet that is not dismissible by tapping on the scrim

* Add guards, improve styling and tests for BottomSheet

* Refresh .arb files

* Refresh localizations

* Set default colorScheme for ButtonThemeData

This changes the DropDownButton so that instead of dismissing itself when any metrics change occurs, it only dismisses itself when the orientation changes.

This gets around the fact that we can't currently have a dropdown and a text field on the same page because the keyboard disappearing when the dropdown gets focus causes a metrics change, and the dropdown immediately disappears when activated.

It still will cause the keyboard to jump up and down between controls, but that's a larger issue. At least now we can use the two together again.

This reverts commit e7616070 because it breaks the framework build.

git@github.com:flutter/engine.git/compare/eed171ff3538...00f330068d3e

git log eed171ff3538..00f330068d3e --no-merges --oneline
2019-10-11 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/mac-amd64 from U4IBp... to ShVbh... (flutter/engine#13092)
2019-10-11 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/linux-amd64 from fk6ou... to LsxeL... (flutter/engine#13083)
2019-10-11 skia-flutter-autoroll@skia.org Roll src/third_party/skia 6c2b2bb02402..df640e6d14a5 (1 commits) (flutter/engine#13080)
2019-10-11 dnfield@google.com Gen package output corrected (flutter/engine#13086)
2019-10-11 dnfield@google.com Print more output when gen_package fails (flutter/engine#13085)


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git@github.com:flutter/engine.git/compare/8dabfb90a110...eed171ff3538

git log 8dabfb90a110..eed171ff3538 --no-merges --oneline
2019-10-11 iska.kaushik@gmail.com [dart_aot_runner] Add rules to generate dart_aot binaries (flutter/engine#13074)
2019-10-11 skia-flutter-autoroll@skia.org Roll src/third_party/skia 7fd7a8aef06c..6c2b2bb02402 (3 commits) (flutter/engine#13079)


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...because otherwise, processes that think they're manipulating your
filesystem will be doing crazy things the test is ignoring, leading to
(at best) failures and (at worst) flakes or disk corruption.

Fixes https://github.com/flutter/flutter/issues/42359

* Revert "Revert "Rewrite MouseTracker's tracking and notifying algorithm (#42031)" (#42478)"

This reverts commit eede7929.

* Fix tests

git@github.com:flutter/engine.git/compare/a5c1c6813091...8dabfb90a110

git log a5c1c6813091..8dabfb90a110 --no-merges --oneline
2019-10-11 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/mac-amd64 from 3GwxH... to U4IBp... (flutter/engine#13078)
2019-10-11 bkonyi@google.com Roll src/third_party/dart 48e93d3d3b..965b8cb1d8 (31 commits)


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git@github.com:flutter/engine.git/compare/e78c3f59c1a1...a5c1c6813091

git log e78c3f59c1a1..a5c1c6813091 --no-merges --oneline
2019-10-11 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/linux-amd64 from v8utw... to fk6ou... (flutter/engine#13072)
2019-10-11 skia-flutter-autoroll@skia.org Roll src/third_party/skia b484e7ce24c9..7fd7a8aef06c (4 commits) (flutter/engine#13069)
2019-10-11 iska.kaushik@gmail.com Reland dart_aot_runner shims
2019-10-11 iska.kaushik@gmail.com Revert "[dart_aot_runner] Add support for generating dart_aot snapshots (#13071)" (flutter/engine#13075)


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git@github.com:flutter/engine.git/compare/cef6751dba87...e78c3f59c1a1

git log cef6751dba87..e78c3f59c1a1 --no-merges --oneline
2019-10-11 iska.kaushik@gmail.com [dart_aot_runner] Add support for generating dart_aot snapshots (flutter/engine#13071)
2019-10-10 chinmaygarde@gmail.com Put Metal renderer selection behind runtime flag and plist opt-in. (flutter/engine#13056)


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The flake appears to be coming from the Google Maps plugin. This test
just needs a platform view plugin without the interface method
implemented in general, not Maps specifically. Update it here to avoid
the issue in Maps until that's fixed.

Create a very simple platform view implementation that exercises this
potential bug in order to create a minimal test case with less risk of
causing second order issues like depending on any kind of full package
would cause.

* Redesigns the algorithm with which MouseTracker keeps track of states and dispatches events. 

Fixes the android_semantics_testing integration test to have the right criteria now that ce150971 has landed.

git@github.com:flutter/engine.git/compare/5162413111b8...cef6751dba87

git log 5162413111b8..cef6751dba87 --no-merges --oneline
2019-10-10 chinmaygarde@gmail.com Revert "Test child isolates are terminated when root is shutdown (#13048)" (flutter/engine#13067)
2019-10-10 garyq@google.com Test child isolates are terminated when root is shutdown (flutter/engine#13048)
2019-10-10 chinmaygarde@google.com Allow embedders to specify arbitrary data to the isolate on launch. (flutter/engine#13047)


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git@github.com:flutter/engine.git/compare/c8f665c3a7b0...5162413111b8

git log c8f665c3a7b0..5162413111b8 --no-merges --oneline
2019-10-10 skia-flutter-autoroll@skia.org Roll src/third_party/skia 69537d798994..b484e7ce24c9 (8 commits) (flutter/engine#13065)
2019-10-10 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/mac-amd64 from xd5Jj... to 3GwxH... (flutter/engine#13064)


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