Move several annotations to annotations package.

base/android/java/src/org/chromium/base/annotations/CalledByNativeUnchecked.java

 // Copyright 2012 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.
 
-package org.chromium.base;
+package org.chromium.base.annotations;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
  *  @CalledByNativeUnchecked is used to generate JNI bindings that do not check for exceptions.
  *  It only makes sense to use this annotation on methods that declare a throws... spec.
  *  However, note that the exception received native side maybe an 'unchecked' (RuntimeExpception)
  *  such as NullPointerException, so the native code should differentiate these cases.
  *  Usage of this should be very rare; where possible handle exceptions in the Java side and use a
  *  return value to indicate success / failure.
  */
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.CLASS)
 public @interface CalledByNativeUnchecked {
     /*
      *  If present, tells which inner class the method belongs to.
      */
     public String value() default "";
 }