Rather than managing all the Material Design icons manually, we now
manage them using an icon font. The icon font contains glyphs for each
icon in an efficient vector format.
This patch updates the FLX tooling to include the MaterialIcons font and
updates the Icon widget to use the font instead of asset images.
Fixes#2313Fixes#2218Fixes#2009Fixes#994
Pulls in the following changed required for iOS:
* Application identifiers are legal UTIs.
* Dart precompiled dylib is not a candidate for dead code stripping.
* Account for relative paths on readlink in SnapshotterInvoke
Downloading these packages from cloud storage simplifies our deployment
story because we can upload to cloud storage automatically from the
buildbot.
This patch also switches the responsibility for downloading the engine
artifacts to update_engine.sh. Centralizing this responsibility ensures
that the packages and the binaries are always in sync.
This patch teaches the flutter command to download the Dart SDK into
cache, removing another step from the Getting Started workflow. The
version of the Dart SDK is controlled by the "dart-sdk.version" file in
the bin/cache directory.
Fixes#54