Add more methods to CWVScrollView and CWVScrollViewDelegate.

ios/web_view/public/cwv_scroll_view.h

Index: ios/web_view/public/cwv_scroll_view.h
diff --git a/ios/web_view/public/cwv_scroll_view.h b/ios/web_view/public/cwv_scroll_view.h
index 4b5c268fdf99371e6a26ba19a6e0ca88a451525d..e076cd07fe505e39d1d4a0f8f2707a836bf41829 100644
--- a/ios/web_view/public/cwv_scroll_view.h
+++ b/ios/web_view/public/cwv_scroll_view.h
@@ -25,8 +25,11 @@ CWV_EXPORT
 
 @property(nonatomic, readonly) CGRect bounds;
 @property(nonatomic) CGPoint contentOffset;
+@property(nonatomic) UIEdgeInsets scrollIndicatorInsets;
 @property(nonatomic, weak) id<CWVScrollViewDelegate> delegate;
+@property(nonatomic, readonly, getter=isDecelerating) BOOL decelerating;
 @property(nonatomic, readonly, getter=isDragging) BOOL dragging;
+@property(nonatomic, readonly) UIPanGestureRecognizer* panGestureRecognizer;
 
 // KVO compliant.
 @property(nonatomic, readonly) CGSize contentSize;
@@ -40,7 +43,9 @@ CWV_EXPORT
 // rdar://23584409 (not available on Open Radar)
 @property(nonatomic) UIEdgeInsets contentInset;
 
+- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated;
 - (void)addGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer;
+- (void)removeGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer;
 
 @end