Add more methods to CWVScrollView and CWVScrollViewDelegate.

ios/web_view/internal/cwv_scroll_view.mm

 // Copyright 2017 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 "ios/web_view/public/cwv_scroll_view.h"
 
 #import "ios/web/public/web_state/ui/crw_web_view_scroll_view_proxy.h"
 #import "ios/web_view/internal/cwv_scroll_view_internal.h"
 #import "ios/web_view/public/cwv_scroll_view_delegate.h"
 
@@ skipping 24 matching lines @@
 }
 
 - (CGPoint)contentOffset {
   return _proxy.contentOffset;
 }
 
 - (void)setContentOffset:(CGPoint)contentOffset {
   _proxy.contentOffset = contentOffset;
 }
 
+- (UIEdgeInsets)scrollIndicatorInsets {
+  return _proxy.scrollIndicatorInsets;
+}
+
+- (void)setScrollIndicatorInsets:(UIEdgeInsets)scrollIndicatorInsets {
+  _proxy.scrollIndicatorInsets = scrollIndicatorInsets;
+}
+
 - (CGRect)bounds {
   return {_proxy.contentOffset, _proxy.frame.size};
 }
 
+- (BOOL)isDecelerating {
+  return _proxy.decelerating;
+}
+
 - (BOOL)isDragging {
   return _proxy.dragging;
 }
 
+- (UIPanGestureRecognizer*)panGestureRecognizer {
+  return _proxy.panGestureRecognizer;
+}
+
 - (UIEdgeInsets)contentInset {
   return _proxy.contentInset;
 }
 
 - (void)setContentInset:(UIEdgeInsets)contentInset {
   _proxy.contentInset = contentInset;
 }
 
+- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated {
+  [_proxy setContentOffset:contentOffset animated:animated];
+}
+
 - (void)addGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer {
   [_proxy addGestureRecognizer:gestureRecognizer];
 }
 
+- (void)removeGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer {
+  [_proxy removeGestureRecognizer:gestureRecognizer];
+}
+
 #pragma mark - NSObject
 
 - (void)dealloc {
   // Removes |self| from |_proxy|'s observers. Otherwise |_proxy| will keep a
   // dangling pointer to |self| and cause SEGV later.
   [_proxy removeObserver:self];
 }
 
 #pragma mark - CRWWebViewScrollViewObserver
 
@@ skipping 26 matching lines @@
 }
 
 - (void)webViewScrollViewDidEndDecelerating:
     (CRWWebViewScrollViewProxy*)webViewScrollViewProxy {
   SEL selector = @selector(webViewScrollViewDidEndDecelerating:);
   if ([_delegate respondsToSelector:selector]) {
     [_delegate scrollViewDidEndDecelerating:self];
   }
 }
 
+- (void)webViewScrollViewWillBeginZooming:
+    (CRWWebViewScrollViewProxy*)webViewScrollViewProxy {
+  SEL selector = @selector(scrollViewWillBeginZooming:);
+  if ([_delegate respondsToSelector:selector]) {
+    [_delegate scrollViewWillBeginZooming:self];
+  }
+}
+
 - (void)webViewScrollViewDidResetContentSize:
     (CRWWebViewScrollViewProxy*)webViewScrollViewProxy {
   self.contentSize = _proxy.contentSize;
 }
 
 @end