[android] Proguard out most of guava

third_party/guava/proguard.flags

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
--keep class com.google.common.base.** {
-  *;
-}
-
--keep class com.google.common.annotations.** {
-  *;
+-keep class com.google.common.annotations.VisibleForTesting,
+            com.google.common.base.Preconditions,
+            com.google.common.base.Objects,
+            com.google.common.base.Strings,
+            com.google.common.base.Supplier {
+    *;
 }
 
 -keepattributes Signature
 
 # Don't complain about usage of sun.misc.Unsafe. Guava imports this,
 # but does not use it unless it exists.
 # The gyp-target that uses this is guava.gyp:guava_javalib.
 -dontwarn sun.misc.Unsafe
 # Striped64 uses reflection to access some local fields.
 -dontnote com.google.common.cache.Striped64
 -dontnote com.google.common.cache.Striped64$Cell
 
 # Keep all enum values and valueOf methods. See
 # http://proguard.sourceforge.net/index.html#manual/examples.html
 # for the reason for this. Also, see http://crbug.com/248037.
 -keepclassmembers enum * {
     public static **[] values();
     public static ** valueOf(java.lang.String);
 }
 
 # Keep finalizer stuff from google-common used via reflection
 -keepclassmembers class com.google.common.** {
   *** finalizeReferent();
 }
 -keepclassmembers class com.google.common.** {
   *** startFinalizer(java.lang.Class,java.lang.Object);
 }