Do not launch external apps while page is scrolling

ios/web/web_state/ui/crw_web_controller.mm

 // 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.
 
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 2988 matching lines @@
 // this for things that should be handled in the subclass instead.
 - (BOOL)shouldAllowLoadWithNavigationAction:(WKNavigationAction*)action {
   NSURLRequest* request = action.request;
   GURL requestURL = net::GURLWithNSURL(request.URL);
 
   // External application launcher needs |isNavigationTypeLinkActivated| to
   // decide if the user intended to open the application by clicking on a link.
   BOOL isNavigationTypeLinkActivated =
       action.navigationType == WKNavigationTypeLinkActivated;
 
-  // Check if the link navigation leads to a launch of an external app.
+  // Checks if the link navigation leads to a launch of an external app.
+  // TODO(crbug.com/704417): External apps will not be launched from clicking
+  // a Bookmarked URL or a Recently Closed URL.
   // TODO(crbug.com/607780): Revise the logic of allowing external app launch
   // and move it to externalAppLauncher.
   BOOL isOpenInNewTabNavigation = !(self.navigationManagerImpl->GetItemCount());
   BOOL isPossibleLinkClick = [self isLinkNavigation:action.navigationType];
-  if (isPossibleLinkClick || isOpenInNewTabNavigation ||
-      PageTransitionCoreTypeIs(self.currentTransition,
-                               ui::PAGE_TRANSITION_AUTO_BOOKMARK)) {
+  if (isPossibleLinkClick || isOpenInNewTabNavigation) {
     web::NavigationItem* item = self.currentNavItem;
     const GURL currentNavigationURL =
         item ? item->GetVirtualURL() : GURL::EmptyGURL();
     // Check If the URL is handled by a native app.
     if ([self urlTriggersNativeAppLaunch:requestURL
                                sourceURL:currentNavigationURL
                  linkActivatedNavigation:isNavigationTypeLinkActivated]) {
       // External app has been launched successfully. Stop the current page
       // load operation (e.g. notifying all observers) and record the URL so
       // that errors reported following the 'NO' reply can be safely ignored.
@@ skipping 348 matching lines @@
   // If page transfer started after last click, user is deemed to be no longer
   // interacting.
   if (!_lastUserInteraction ||
       _lastTransferTimeInSeconds > _lastUserInteraction->time) {
     return NO;
   }
   return [self userClickedRecently];
 }
 
 - (BOOL)userClickedRecently {
+  // Scrolling generates a pair of touch on/off event which causes
+  // _lastUserInteraction to register that there was user interaction.
+  // Checks for scrolling first to override time-based click heuristics.
+  BOOL scrolling = [[self webScrollView] isDragging] ||
+                   [[self webScrollView] isDecelerating];
+  if (scrolling)
+    return NO;
   if (!_lastUserInteraction)
     return NO;
   return _clickInProgress ||
          ((CFAbsoluteTimeGetCurrent() - _lastUserInteraction->time) <
           kMaximumDelayForUserInteractionInSeconds);
 }
 
 #pragma mark Placeholder Overlay Methods
 
 - (void)addPlaceholderOverlay {
@@ skipping 1680 matching lines @@
 - (void)simulateLoadRequestWithURL:(const GURL&)URL {
   _lastRegisteredRequestURL = URL;
   _loadPhase = web::LOAD_REQUESTED;
 }
 
 - (NSString*)referrerFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:kReferrerHeaderName];
 }
 
 @end