Link dart:* sources into engine for debugger source support
Currently, dart:* libraries appear to have no source in
debuggers like Observatory. With this change, these sources will be
available in debug mode applications. Sources for dart:* libraries are
lazily loaded on a script-by-script basis.
Refer to https://dart-review.googlesource.com/c/sdk/+/93375 for the Dart
SDK change.
If an app is using retainFlutterNativeView or a plugin wants to keep the
FlutterNativeView active, then the FlutterNativeView should not drop its
handle to the corresponding native platform view.
Fixes https://github.com/flutter/flutter/issues/26931
From build log:
```
../../flutter/shell/platform/android/io/flutter/view/FlutterView.java:95: error: cannot find symbol
private final LocalizationChannel localizationChannel;
^
symbol: class LocalizationChannel
location: class FlutterView
../../flutter/shell/platform/android/io/flutter/view/FlutterView.java:172: error: cannot find symbol
localizationChannel = new LocalizationChannel(dartExecutor);
^
symbol: class LocalizationChannel
location: class FlutterView
2 errors
```
This reverts commit 256db4bc23b7931509233df0dc04e44e16608229.
Prior to this the Android embedder code would extract the icudtl.dat asset out
of the APK and write it to local disk during the first startup of the app.
This change will make that work unnecessary and eliminate the risk of ICU
failures due to errors in the extraction process.
Behavior (visual) changes should be very minor. Things that are to be expected:
* A few things were not color managed correctly by the transform canvas (color emoji, some color filters). Those will be handled correctly with the tagged surfaces (although we're always transforming to sRGB, so nothing should change until we target a wider gamut).
* Image filtering will happen in the source color space, rather than the destination. Very minor.
* The transform canvas did caching of images in the destination color space. Now, the conversion happens at draw time. If there are performance issues, images can be pre-converted to the destination with makeColorSpace().
This change adds explicit validation of dynamic patches in all places
where they're used, instead of only validating it in some places which
wasn't as reliable because some of the code paths were missed.
This change also moves utility functions that deal with validating
patches from ResourceExtractor to ResourceUpdater, to make them
available as API for other places in code that need this validation.
This fixes potential race condition when patch gets downloaded on top
of zip file that's currently in active use by resource extractor and/or
asset manager. This change is necessary since download can happen in
the background while normal application operations are in progress.
This is a no-op change, except for fixing a bug where download task
reference wasn't cleared after download was completed.
This change also removes call to output stream flush(), which is not
necessary according to Java spec.
The rest of the change deals with requiring the code to work directly
with ResourceUpdater object instead of having FlutterMain be a facade
that forwards some of ResourceUpdater's methods. This simplifies the
other (more essential) upcoming changes that will be landing in the
followings few PRs.
