Add a -keep for all Parcelables in hopes it fixes crash in the wild

base/android/base_proguard_config.flags

 # Keep line number information, useful for stack traces.
 -keepattributes SourceFile,LineNumberTable
 
 # Keep all annotation related attributes that can affect runtime
 -keepattributes RuntimeVisible*Annotations
 -keepattributes AnnotationDefault
 
 # Keep the annotations, because if we don't, the ProGuard rules that use them
 # will not be respected. These classes then show up in our final dex, which we
 # do not want - see crbug.com/628226.
@@ skipping 19 matching lines @@
 -keepclasseswithmembers,includedescriptorclasses class * {
   @org.chromium.base.annotations.CalledByNativeUnchecked <methods>;
 }
 -keepclasseswithmembers class * {
   @org.chromium.base.annotations.UsedByReflection <methods>;
 }
 -keepclasseswithmembers,includedescriptorclasses class * {
   native <methods>;
 }
 
-# Keep all Parcelables as they might be marshalled outside Chrome.
--keepnames class * implements android.os.Parcelable
-
+# Keep all CREATOR fields within Parcelable that are kept.
 -keepclassmembers class * implements android.os.Parcelable {
   public static *** CREATOR;
 }
 
+# Don't obfuscate Parcelables as they might be marshalled outside Chrome.
+-keepnames class * implements android.os.Parcelable
+
+# Keep all Parcelables, since Play Services has some that are used only by
+# reflection.
+# TODO(agrieve): Remove this once proguard flags provided by play services via
+#     .aars are used.

[nyquist, 2016/08/24 21:16:12]

Nit: Is there a bug for this?

[agrieve, 2016/08/25 01:00:53]

Good call. Added.

+-keep class * implements android.os.Parcelable
+
 # Remove methods annotated with this if their return value is unused
 -assumenosideeffects class ** {
   @org.chromium.base.annotations.RemovableInRelease <methods>;
 }
 
 # 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();
 }