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

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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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This attempts to reland #40186 and #41220, that were reverted in #41945.

The main modifications from the original PRs are that I predefine the shortcuts and actions maps instead of defining them inline in the build function, and I use a new mapEquals to do a deep comparison so that we don't rebuild modified things if the contents of the map haven't changed.

I also eliminated an operator== and hashCode that were defined on the Actions widget, since widgets shouldn't have those. (it's too bad though: I get an 85% speedup if we leave this in! Too bad it prevents rebuilding of the children...)

Fixes #40101

* Adds a new parameter bool opaque to MouseRegion
* The same to RenderMouseRegion and AnnotatedRegionLayer
* Add findAnnotations to Layer 

Currently the surface of a platform view is only created only one when the state of PlatformViewLink is created. When the PlatformViewLink widget changes, the PlatformViewController in the corresponding state is also updated. Just the surface is not updated even though it depends on the controller.

This PR changes this behavior to recreate the surface whenever the controller is updated.

git@github.com:flutter/engine.git/compare/0b6aa5e3201a...c8f665c3a7b0

git log 0b6aa5e3201a..c8f665c3a7b0 --no-merges --oneline
2019-10-10 jason-simmons@users.noreply.github.com Allow embedders to disable causal async stacks in the Dart VM (flutter/engine#13004)
2019-10-10 jason-simmons@users.noreply.github.com Integration with more of Skia's SkShaper/SkParagraph APIs (flutter/engine#13008)


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git@github.com:flutter/engine.git/compare/a05803a0d2ba...0b6aa5e3201a

git log a05803a0d2ba..0b6aa5e3201a --no-merges --oneline
2019-10-10 yjbanov@google.com Add "felt clean" command (flutter/engine#13042)
2019-10-10 skia-flutter-autoroll@skia.org Roll src/third_party/skia 0fc9b3829b47..69537d798994 (1 commits) (flutter/engine#13061)


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Bytecode generation will otherwise omit prologue code, causing --causal-async-stacks passed to the VM to behave inconsistently.

Also updated the documentation for the ThemeData constructor to include
descriptions of parameters that don't map to specific fields directly.

1. The platform code to show the keyboard wasn't working on certain
devices. From my testing it appears to be related to when the code was
firing. IMM won't show the soft input (or shows and then immediately
hides it, it's hard to tell) if it's called before the Flutter UI is
loaded. Change this to instead show the soft keyboard after a message
from Flutter that main() has been started.

2. A text field was visible in the UI, and the test was run under a
fuzzer that random tapped portions of the screen. Remove the text field
so that the fuzzer can't accidentally open the keyboard on its own at a
random time.

3. The keyboard was left open even after the app was closed. Also toggle
the input off when the app was closed, so that this test can be ran
multiple times in succession relatively hermetically.

[BUG] Process all children of intent-filter instead of just the first one to identify default activity (#40029)

git@github.com:flutter/engine.git/compare/d25a623d7f90...a05803a0d2ba

git log d25a623d7f90..a05803a0d2ba --no-merges --oneline
2019-10-10 dnfield@google.com Android targets create final zip artifacts (flutter/engine#13059)
2019-10-10 sjindel@google.com Remove use of the blobs snapshot format from unittests (flutter/engine#12563)


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d25a623d7 Roll fuchsia/sdk/core/linux-amd64 from QIjex... to v8utw... (flutter/engine#13060) (#42425)


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2019-10-10 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/linux-amd64 from QIjex... to v8utw... (flutter/engine#13060)


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Shard web tests; enable semantics tests on the Web

5a8605444 Roll src/third_party/skia fe23b1de9ed0..0fc9b3829b47 (1 commits) (flutter/engine#13058) (#42412)


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2019-10-10 skia-flutter-autoroll@skia.org Roll src/third_party/skia fe23b1de9ed0..0fc9b3829b47 (1 commits) (flutter/engine#13058)


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git@github.com:flutter/engine.git/compare/ed1557f82dd4...f237896bac7c

git log ed1557f82dd4..f237896bac7c --no-merges --oneline
2019-10-10 bkonyi@google.com Roll src/third_party/dart cc3e22f724..48e93d3d3b (8 commits)
2019-10-10 skia-flutter-autoroll@skia.org Roll fuchsia/sdk/core/mac-amd64 from pczjK... to xd5Jj... (flutter/engine#13055)
2019-10-10 dnfield@google.com Minimal test harness for iOS (flutter/engine#13029)


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* Capture stdout in test helper

* Simplify running getPackages() in test utils

* Remove unused import

git@github.com:flutter/engine.git/compare/179fab9dcbac...ed1557f82dd4

git log 179fab9dcbac..ed1557f82dd4 --no-merges --oneline
2019-10-10 chinmaygarde@google.com Don’t bump iOS deployment target for Metal builds. (flutter/engine#13051)
2019-10-10 duanweiwei1982@gmail.com Add texture support for macOS shell. (flutter/engine#8507)


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