[Android] Add missing @VisibleForTesting annotations.

base/BUILD.gn

 # Copyright (c) 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.
 
 import("//build/config/ui.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
@@ skipping 1389 matching lines @@
       "android/java/src/org/chromium/base/BuildInfo.java",
       "android/java/src/org/chromium/base/TraceEvent.java",
       "android/java/src/org/chromium/base/AccessedByNative.java",
       "android/java/src/org/chromium/base/JNINamespace.java",
       "android/java/src/org/chromium/base/CalledByNativeUnchecked.java",
       "android/java/src/org/chromium/base/MemoryPressureListener.java",
       "android/java/src/org/chromium/base/NativeClassQualifiedName.java",
       "android/java/src/org/chromium/base/ActivityState.java",
       "android/java/src/org/chromium/base/ApplicationStatus.java",
       "android/java/src/org/chromium/base/ApiCompatibilityUtils.java",
+      "android/java/src/org/chromium/base/VisibleForTesting.java",
     ]
 
     # A new version of NativeLibraries.java (with the actual correct values)
     # will be created when creating an apk.
     jar_excluded_patterns = [
       "*/NativeLibraries.class",
       "*/NativeLibraries##*.class",
     ]
   }
 
@@ skipping 35 matching lines @@
 
   unittest_apk("base_unittests_apk") {
     deps = [
       ":base_java",
       ":base_java_unittest_support",
       ":base_unittests",
     ]
     unittests_dep = ":base_unittests"
   }
 }