Removed keeps for unused member variables.

chrome/android/java/proguard.flags

 # Keep line number information, useful for stack traces.
 -keepattributes SourceFile,LineNumberTable
 
 # Keep the annotations.
 -keep @interface ***
 
 # Disable obfuscation for the following two packages.
 -keepnames class com.google.android.apps.chrome.**,org.chromium.** {
   *;
 }
@@ skipping 205 matching lines @@
 -dontwarn org.apache.http.conn.scheme.LayeredSocketFactory
 
 # Needed to run ChromeTest.apk
 -keepnames class com.google.android.gms.common.GoogleApiAvailability {
   *;
 }
 
 # Needed for chrome_sync_shell_test_apk. Note - these do no affect chrome_apk's
 # size.
 -keep class org.chromium.sync.protocol.* { *; }
+
+# These resources are referenced in tests, but not in the real application.
+-keepclassmembers class org.chromium.chrome.R$id {
+  int webapp_splash_space;
+  int mr_chooser_list;
+  int find_toolbar;
+}