The transitive dependency on the embedder library brings in the right
runtime for the build mode, so directly depending on the JIT version
isn't necessary, and causes duplicate symbol issues in release builds.

I fixed a bug that left a blank at the bottom of the screen when the iPad's split keyboard was hidden.

I also had the same problem with this issue, so I fixed it.
iPad split keyboard cause a blank space problem

There is no function to change the space size at the bottom of the screen when the split keyboard is moved. This is because it's not clear what the keyboard should do when it's moved to the top of the screen.

Previously the build scripts obtained the lambda support classes from rt.jar,
which is no longer provided by recent versions of the JDK.

Test failure:

    [ RUN      ] FlutterStringCodec.CanEncodeAndDecodeNil
    2020-04-07 10:21:25.091 flutter_channels_unittests[26965:163315] *** Assertion failure in -[FlutterStringCodec encode:], ../../flutter/shell/platform/darwin/common/framework/Source/FlutterCodecs.mm:36
    2020-04-07 10:21:25.118 flutter_channels_unittests[26965:163315] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: ''
    *** First throw call stack:
    (
    	0   CoreFoundation                      0x00007fff2ccabcf9 __exceptionPreprocess + 256
    	1   libobjc.A.dylib                     0x00007fff5785ea17 objc_exception_throw + 48
    	2   CoreFoundation                      0x00007fff2ccc6a16 +[NSException raise:format:arguments:] + 98
    	3   Foundation                          0x00007fff2ef58e11 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 194
    	4   flutter_channels_unittests          0x0000000105f1cce2 -[FlutterStringCodec encode:] + 290
    	5   flutter_channels_unittests          0x0000000105f01bbb _ZN45FlutterStringCodec_CanEncodeAndDecodeNil_Test8TestBodyEv + 107
    	6   flutter_channels_unittests          0x00000001081d1732 _ZN7testing8internal38HandleSehExceptionsInMethodIfSupportedINS_4TestEvEET0_PT_MS4_FS3_vEPKc + 146
    	7   flutter_channels_unittests          0x00000001081a76b0 _ZN7testing8internal35HandleExceptionsInMethodIfSupportedINS_4TestEvEET0_PT_MS4_FS3_vEPKc + 128
    	8   flutter_channels_unittests          0x00000001081a75c1 _ZN7testing4Test3RunEv + 209
    	9   flutter_channels_unittests          0x00000001081a8415 _ZN7testing8TestInfo3RunEv + 229
    	10  flutter_channels_unittests          0x00000001081a95aa _ZN7testing9TestSuite3RunEv + 266
    	11  flutter_channels_unittests          0x00000001081b4e43 _ZN7testing8internal12UnitTestImpl11RunAllTestsEv + 995
    	12  flutter_channels_unittests          0x00000001081d8572 _ZN7testing8internal38HandleSehExceptionsInMethodIfSupportedINS0_12UnitTestImplEbEET0_PT_MS4_FS3_vEPKc + 146
    	13  flutter_channels_unittests          0x00000001081b49b3 _ZN7testing8internal35HandleExceptionsInMethodIfSupportedINS0_12UnitTestImplEbEET0_PT_MS4_FS3_vEPKc + 131
    	14  flutter_channels_unittests          0x00000001081b4835 _ZN7testing8UnitTest3RunEv + 197
    	15  flutter_channels_unittests          0x0000000105f22e73 _Z13RUN_ALL_TESTSv + 35
    	16  flutter_channels_unittests          0x0000000105f22d79 main + 553
    	17  libdyld.dylib                       0x00007fff5908c3d5 start + 1
    )
    libc++abi.dylib: terminating with uncaught exception of type NSException
    [ERROR:flutter/fml/backtrace.cc(110)] Caught signal SIGABRT during program execution.
    Frame 0: 0x7fff591316a6 abort
    Frame 1: 0x7fff560ea641 __cxa_bad_cast
    Frame 2: 0x7fff560ea7df default_unexpected_handler()�
    Frame 3: 0x7fff57860ee3 _objc_terminate()�
    Frame 4: 0x7fff560f619e std::__terminate(void (*)())�
    Frame 5: 0x7fff560f5f86 __cxa_get_exception_ptr
    Frame 6: 0x7fff560e8f99 __cxa_get_globals
    Frame 7: 0x7fff5785eb51 objc_exception_throw
    Frame 8: 0x7fff2ccc6a16 +[NSException raise:format:arguments:]
    Frame 9: 0x7fff2ef58e11 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:]
    Frame 10: 0x105f1cce2 -[FlutterStringCodec encode:]
    Frame 11: 0x105f01bbb FlutterStringCodec_CanEncodeAndDecodeNil_Test::TestBody()�
    Frame 12: 0x1081d1732 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*)�
    Frame 13: 0x1081a76b0 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*)�
    Frame 14: 0x1081a75c1 testing::Test::Run()�
    Frame 15: 0x1081a8415 testing::TestInfo::Run()�
    Frame 16: 0x1081a95aa testing::TestSuite::Run()�
    Frame 17: 0x1081b4e43 testing::internal::UnitTestImpl::RunAllTests()�
    Frame 18: 0x1081d8572 bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*)�
    Frame 19: 0x1081b49b3 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*)�
    Frame 20: 0x1081b4835 testing::UnitTest::Run()�
    Frame 21: 0x105f22e73 RUN_ALL_TESTS()�
    Frame 22: 0x105f22d79 main
    Frame 23: 0x7fff5908c3d5 start

This reverts commit d1c90b42.

Seems to have triggered flaky failures on the Windows bot since landing.
Example failure:

    [ RUN      ] PluginRegistrarTest.ManagerRemovesOnDestruction
    c:\b\s\w\ir\cache\builder\src\flutter\shell\platform\common\cpp\client_wrapper\plugin_registrar_unittests.cc(149): error: Expected: (manager->GetRegistrar<PluginRegistrar>(dummy_registrar_handle)) != (first_wrapper), actual: 000002400A90E3D0 vs 000002400A90E3D0

This reverts commit faf44fed.

"unrecognized-selector" and "overriding-method-mismatch" added as errors.

This makes two changes:
- Adds a way to register a callback for when a FlutterDesktopPluginRegistrarRef is destroyed, and implements the logic to call it in the Windows and Linux embeddings.
- Adds a class to the C++ wrapper that handles making a singleton owning PluginRegistrar wrappers, and destroying them when the underlying reference goes away, to avoid needing that boilerplate code in every plugin's source.

Fixes https://github.com/flutter/flutter/issues/53496

This change also adds TimeRecorder which records time at the start
of each frame to capture the latest vsync target display time and
wires it in to the rasterizer to add trace events when there is a lag.

The JSON codec is awkward to use in the wrapper (since the client has to build and link one of the JSON libraries to do so). Since it would be very cumbersome to wrap in a C API, and there's essentially no reason to use it instead of the standard codec, this removes it from the wrapper entirely.

Since some system channels (internal to the engine) still use it, it's moved into common/cpp instead of being eliminated entirely. Internally we always use RapidJSON though, so the jsoncpp implementation is removed. Also adds some unit test coverage, since there wasn't any.

Fixes #30669

* "Reland Clang 11, roll buildroot to 1bc40a5f916adb93d87e2a2230a0ec43db876c1c, take 4 (#17467)" (#17482)"

This reverts commit 8166a91b.

* format code

* Roll buildroot to 3a27de1c5bb0f50be7d3efe3e00de4f6068c9f30

There is no ability to compile shaders online and cache those binaries when
using the Metal backend. SkSL caching must always be used.

* Initialize locale from FlutterEngine

Revert "Reland Clang 11, roll buildroot to 1bc40a5f916adb93d87e2a2230a0ec43db876c1c, take 3 (#17467)" (#17482)

This reverts commit 39b77188.

* Reland Clang 11, Roll buildroot to 1bc40a5f916adb93d87e2a2230a0ec43db876c1c (#17457)" (#17464)

This reverts commit 9eacd028.

* Skip more image tests, use newer dsymutil, add missing symbols

Revert "Reland Clang 11, Roll buildroot to 1bc40a5f916adb93d87e2a2230a0ec43db876c1c (#17457)" (#17464)

This reverts commit a4026cc9.

* Reland "Roll Clang to v11, roll buildroot to fe13f79dce4ce9aab3209f11988d825dcf580b4a, allow newly exported symbols (#17440)" (#17451)"

This reverts commit a870bc53.

* skip golden that is different on macos

* buildroot to 1bc40a5f916adb93d87e2a2230a0ec43db876c1c

Started clearing out the semantics information in Dart as well as deleting the AccessibilityBridge. (#17433)

API staging is complete - these defines have been removed.

Fixes https://github.com/flutter/flutter/issues/18208. All Metal for iOS related work items described in https://github.com/orgs/flutter/projects/5 have been completed.

If the application says there is a new texture but does not provide one, reuse the last texture. (#17437)

This matches the behavior of the OpenGL backend.

Matches the structure used on Windows of assuming a directory format.

The following issues have been filed to track the handling of these enum values:

* Handle the UITouchTypeIndirectPointer enum value. https://github.com/flutter/flutter/issues/53696
* Handle the UITouchPhaseRegion enum values. https://github.com/flutter/flutter/issues/53695

No change in functionality. Only makes the iOS engine build on the latest
versions of Xcode and iOS SDK. The enum values cannot be used with the
API_AVAILABLE macro because the buildbots have not been updated yet.

Since the trace provider hasn't been created yet, it is not possible to
trace the creation of a trace provider using a TRACE_DURATION event (the
trace enabled and category check will always fail).  While this isn't
causing any urgent problems, remove it to set a good example for other
clients of tracing that might happen to reference this code.

Make the test robust even if the json map reorders its keys.

This PR touches variable names, class names, and file names so it's significantly more risky than its predecessor https://github.com/flutter/engine/pull/17329

Due to file name changes, this PR is expected to change the license files.

We haven't rename `shell/gpu` to `shell/raster` yet. It should be optional but I think it's better to have `raster_surface_software.cc` than `gpu_surface_software.cc`.