1229269 - Remove all uses Resources.getResourceIdentifier from Fennec to enable Gradle's shrinkResources

Status: NEW

(Firefox Build System :: Android Studio and Gradle Integration, defect)

Description

[Nick Alexander :nalexander [he/him]]

This ticket tracks enabling Gradle's "shrinkResources" option (see http://tools.android.com/tech-docs/new-build-system/resource-shrinking).  In fact, this is easy -- but more or less useless, since Resources.getResourceIdentifier stymies the analysis, marking almost all resources as "reachable" since they match an overly broad prefix.  (See https://android.googlesource.com/platform/tools/base/+/70835c6423962449ba7032ee4ee19ec096e8c5ff/build-system/gradle-core/src/main/groovy/com/android/build/gradle/tasks/ResourceUsageAnalyzer.java#2448, which I believe is current as of com.android.tools.build:gradle:2.0.0-alpha1.)

There are ways to improve this by setting some flags and using tools prefixes, but perhaps we can figure out how to just do better.  There are only about 3 consumers of getIdentifiers() in the tree (see https://dxr.mozilla.org/mozilla-central/search?q=getIdentifier+path%3A*.java&redirect=true&case=false) although they actually appear legitimate.