Remove unused proguard -keep for android.webkit.JavascriptInterface

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.
 -keep @interface org.chromium.base.annotations.AccessedByNative
 -keep @interface org.chromium.base.annotations.CalledByNative
 -keep @interface org.chromium.base.annotations.CalledByNativeUnchecked
 -keep @interface org.chromium.base.annotations.RemovableInRelease
 -keep @interface org.chromium.base.annotations.UsedByReflection
 
 # Keeps for class level annotations.
 -keep @org.chromium.base.annotations.UsedByReflection class *
 
 # Keeps for method level annotations.
--keepclassmembers class * {
-  @android.webkit.JavascriptInterface <methods>;
-}
 -keepclasseswithmembers class * {
   @org.chromium.base.annotations.AccessedByNative <fields>;
 }
 -keepclasseswithmembers,includedescriptorclasses class * {
   @org.chromium.base.annotations.CalledByNative <methods>;
 }
 -keepclasseswithmembers,includedescriptorclasses class * {
   @org.chromium.base.annotations.CalledByNativeUnchecked <methods>;
 }
 -keepclasseswithmembers class * {
@@ skipping 19 matching lines @@
   @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();
 }