This consolidates all of the non-template .gitignore rules into the top level .gitignore, to ignore common things more broadly, with less maintenance needed for the .gitignore files. Does not touch the templates, so that they still produce needed .gitignores as part of flutter create.
* Add framework-side support for system text scale factor.
* Rolling engine to e3404b81a53ba3180c7623a6f2190ebb28518f30
Additional changes rolled in with engine change:
libtxt: implementation of GetRectsForRange that processes a line at a time - e3404b8
Provide an entropy source to the Dart engine (#4161) - e1aa867
libtxt: search for fallback fonts that can match emoji and CJK characters - 8061df1
Roll skia to e4679fa06a. (#4157) - 267e7a8
Update buildroot to 53fea9aebbcc39c6522731471a1a45960ee0685e (#4160) - 02ea7ae
Revert engine Dart roll. (#4158) - 14aab33
Add support for system text scale factor. (#4124) - b2a7f4b
Include _http into sky_engine libraries for analyzer (#4154) - b930f10
libtxt: Remove postprocess_line and improve tracking of X offsets - 86f95f0
libtxt: remove redundant line_widths (#4152) - 14bf515
Roll dart to ade37f931e90b0fdb8fe16d6bf6f089545da55b6 (#4151) - 6f1264f
Gradle projects are evaluated in lexicographical order, and the plugin
projects are at the same level as the :app project, so if a plugin has
a name that comes before 'app' (like, for example, any name that starts
with a capital letter), the plugin project will be evaluated before
:app.
Since :app applies the Flutter Gradle plugin, which tries to
modify the dependencies of the plugin projects, we have a problem if the
plugin projects have already been evaluated. Adding
evaluationDependsOn(':app') to the plugin projects fixes this.
Updated example projects to the latest (plugin-enabled) Gradle build
files.
Also removed two unused imports in `pluginClass.java.tmpl`.
