import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

mobile/android/config/proguard/strip-libs.cfg

@@ -0,0 +1,41 @@
+# Proguard step for stripping debug information.
+#
+# This is useful to work around a bug in the way Proguard handles debug information: it
+# sometimes corrupts it. Classes with corrupt debug information cannot be dexed, but
+# classes with *no* debug information can be. There's no way to configure Proguard to
+# delete debug information on a per-class basis, so we need this special extra step for
+# stripping debug information only from those classes for which the Proguard bug is
+# encountered.
+#
+# Currently, this pass is applied to all bundled library jars for which we are not
+# compiling the source. This is slightly more than is strictly necessary to work around
+# the Proguard bug, but such debug information is of negligible value and stripping it
+# too slightly simplifies the makefile and saves us a handful of kilobytes of binary size.
+#
+# Configuring Proguard to do nothing except strip metadata is done by having it run only
+# the obfuscation pass, but with a configuration that prevents it from renaming any classes.
+# It then attempts to delete class metadata, so we further configure it not to do so for
+# anything except the problematic debug information.
+
+# Run only the obfuscator.
+-dontoptimize
+-dontshrink
+-dontpreverify
+-verbose
+
+# Don't rename anything.
+-keeppackagenames
+
+# Seriously, don't rename anything.
+-keep class *
+-keepclassmembers class * {
+    *;
+}
+
+# Don't delete other useful metadata.
+-keepattributes Exceptions,InnerClasses,Signature,Deprecated,*Annotation*,EnclosingMethod
+
+# Don't print spurious warnings from the support library.
+# See: http://stackoverflow.com/questions/22441366/note-android-support-v4-text-icucompatics-cant-find-dynamically-referenced-cl
+-dontnote android.support.**
+-dontwarn android.support.**