Improve page transition type heuristic in WebController

ios/web/web_state/ui/crw_wk_web_view_web_controller.mm

Index: ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
diff --git a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
index 5405dbe580cd0c94ffce0a1927bbf93baed96726..a4bc4c44d813e0a49d69823b414e42fc3c8b94fd 100644
--- a/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
+++ b/ios/web/web_state/ui/crw_wk_web_view_web_controller.mm
@@ -144,6 +144,9 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
   // Cancelled navigations should be simply discarded without handling any
   // specific error.
   BOOL _pendingNavigationCancelled;
+
+  // YES if the user has touched the content area since the last URL change.
+  BOOL _touchedSinceLastURLChange;
 }
 
 // Response's MIME type of the last known navigation.
@@ -368,6 +371,12 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
   [super close];
 }
 
+- (void)touched:(BOOL)touched {
+  [super touched:touched];
+  if (touched)
+    _touchedSinceLastURLChange = YES;
+}
+
 #pragma mark -
 #pragma mark Testing-Only Methods
 
@@ -1014,14 +1023,36 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
 #endif  // !defined(ENABLE_CHROME_NET_STACK_FOR_WKWEBVIEW)
 
 - (void)registerLoadRequest:(const GURL&)url {
-  // If load request is registered via WKWebViewWebController, assume transition
-  // is link or client redirect as other transitions will already be registered
-  // by web controller or delegates.
-  // TODO(stuartmorgan): Remove guesswork and replace with information from
-  // decidePolicyForNavigationAction:.
-  ui::PageTransition transition = self.userInteractionRegistered
-                                      ? ui::PAGE_TRANSITION_LINK
-                                      : ui::PAGE_TRANSITION_CLIENT_REDIRECT;
+  // Get the navigation type from the last main frame load request, and try to
+  // map that to a PageTransition.
+  WKNavigationType navigationType = _pendingNavigationTypeForMainFrame
+                                        ? *_pendingNavigationTypeForMainFrame
+                                        : WKNavigationTypeOther;
+  ui::PageTransition transition = ui::PAGE_TRANSITION_CLIENT_REDIRECT;
+  switch (navigationType) {
+    case WKNavigationTypeLinkActivated:
+      transition = ui::PAGE_TRANSITION_LINK;
+      break;
+    case WKNavigationTypeFormSubmitted:
+    case WKNavigationTypeFormResubmitted:
+      transition = ui::PAGE_TRANSITION_FORM_SUBMIT;
+      break;
+    case WKNavigationTypeBackForward:
+      transition = ui::PAGE_TRANSITION_FORWARD_BACK;
+      break;
+    case WKNavigationTypeReload:
+      transition = ui::PAGE_TRANSITION_RELOAD;
+      break;
+    case WKNavigationTypeOther:
+      // The "Other" type covers a variety of very different cases, which may
+      // or may not be the result of user actions. For now, guess based on
+      // whether there's been a touch since the last URL change.
+      // TODO(crbug.com/549301): See if this heuristic can be improved.
+      transition = _touchedSinceLastURLChange
+                       ? ui::PAGE_TRANSITION_LINK
+                       : ui::PAGE_TRANSITION_CLIENT_REDIRECT;
+      break;
+  }
   // The referrer is not known yet, and will be updated later.
   const web::Referrer emptyReferrer;
   [self registerLoadRequest:url referrer:emptyReferrer transition:transition];
@@ -1226,6 +1257,8 @@ WKWebViewErrorSource WKWebViewErrorSourceFromError(NSError* error) {
     return;
   }
   GURL url(net::GURLWithNSURL([_wkWebView URL]));
+  if (url != _documentURL)
+    _touchedSinceLastURLChange = NO;

[Eugene But (OOO till 7-30), 2015/10/30 15:10:47]

This is not the only place where _documentURL is changed. How about adding
- (void)setDocumentURL: (const GURL&)newURL {
  if (_documentURL != newURL) {
    _documentURL = newURL;
    _touchedSinceLastURLChange = NO;
  }
}

and calling it everywhere instead of assigning value to ivar?

[stuartmorgan, 2015/10/30 16:00:01]

Originally I didn't do that because of the async code in URL change detection
below, but on further consideration keeping the relative ordering makes sense,
and this is a less fragile approach. Done.

   // URL changes happen at three points:
   // 1) When a load starts; at this point, the load is provisional, and
   //    it should be ignored until it's committed, since the document/window