Remove unused proguard -keep for android.webkit.JavascriptInterface

base/android/base_proguard_config.flags

Index: base/android/base_proguard_config.flags
diff --git a/base/android/base_proguard_config.flags b/base/android/base_proguard_config.flags
index d3089d816495164f2d4ddfce78cc44a27b2fda92..bd860c51ccad69a3c28674a92a2b0b6b85dc3ca2 100644
--- a/base/android/base_proguard_config.flags
+++ b/base/android/base_proguard_config.flags
@@ -18,9 +18,6 @@
 -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>;
 }