title: Change height of inputAccessoryView issue
body: <p>When I change the height of <code>inputAccessoryView</code> in iOS 8, the inputAccessoryView not go to the right origin, but covers the keyboard.</p>
  
  <p><img src="https://i.stack.imgur.com/EJfQo.jpg" alt="enter image description here"></p>
  
  <p>Here are some code snippets:</p>
  
  <h1>in table view controller</h1>
  
  <pre><code>- (UIView *)inputAccessoryView {
      if (!_commentInputView) {
          _commentInputView = [[CommentInputView alloc] initWithFrame:CGRectMake(0, 0, [self width], 41)];
          [_commentInputView setPlaceholder:NSLocalizedString(@"Comment", nil) andButtonTitle:NSLocalizedString(@"Send", nil)];
          [_commentInputView setBackgroundColor:[UIColor whiteColor]];
          _commentInputView.hidden = YES;
          _commentInputView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleBottomMargin;
      }
  
      return _commentInputView;
  }
  </code></pre>
  
  <h1>in CommentInputView</h1>
  
  <pre><code>#when the textview change height
  - (void)growingTextView:(HPGrowingTextView *)growingTextView willChangeHeight:(float)height {
      if (height &gt; _textView_height) {
          [self setHeight:(CGRectGetHeight(self.frame) + height - _textView_height)];
          [self reloadInputViews];
      }
  }
  </code></pre>
  
  <h1>in UIView Category from <a href="https://github.com/eleven-huang/ios-helpers" rel="noreferrer">ios-helpers</a></h1>
  
  <pre><code>- (void)setHeight: (CGFloat)heigth {
      CGRect frame = self.frame;
      frame.size.height = heigth;
      self.frame = frame;
  }
  </code></pre>