Wire up download attribution enable finch experiment

chrome/browser/safe_browsing/safe_browsing_navigation_observer.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/safe_browsing/safe_browsing_navigation_observer.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.h"
 #include "chrome/browser/sessions/session_tab_helper.h"
@@ skipping 52 matching lines @@
   has_committed = nav_event.has_committed;
   has_server_redirect = nav_event.has_server_redirect;
   return *this;
 }
 
 NavigationEvent::~NavigationEvent() {}
 
 // SafeBrowsingNavigationObserver --------------------------------------------
 
 // static
-void SafeBrowsingNavigationObserver::MaybeCreateForWebContents(
-    content::WebContents* web_contents) {
-  if (FromWebContents(web_contents))
-    return;
-  // TODO(jialiul): This method will be called by TabHelpers::AttachTabHelpers.
-  // Complete this method when the entire class is ready.
-  NOTIMPLEMENTED();
+void SafeBrowsingNavigationObserver::CreateForWebContents(
+    content::WebContents* web_contents,
+    const scoped_refptr<SafeBrowsingNavigationObserverManager>& manager) {
+  if (!FromWebContents(web_contents)) {
+    web_contents->SetUserData(
+        kWebContentsUserDataKey,
+        new SafeBrowsingNavigationObserver(web_contents, manager));
+  }
 }
 
 // static
 SafeBrowsingNavigationObserver* SafeBrowsingNavigationObserver::FromWebContents(
     content::WebContents* web_contents) {
   return static_cast<SafeBrowsingNavigationObserver*>(
       web_contents->GetUserData(kWebContentsUserDataKey));
 }
 
 SafeBrowsingNavigationObserver::SafeBrowsingNavigationObserver(
@@ skipping 18 matching lines @@
   // we need to copy the is_user_initiated field.
   if (it != navigation_handle_map_.end()) {
     nav_event.is_user_initiated = it->second.is_user_initiated;
   } else {
     // If this is the first time we see this navigation_handle, create a new
     // NavigationEvent, and decide if it is triggered by user.
     if ((has_user_gesture_ &&
          !SafeBrowsingNavigationObserverManager::IsUserGestureExpired(
              last_user_gesture_timestamp_)) ||
         !navigation_handle->IsRendererInitiated()) {
-      nav_event.is_user_initiated = has_user_gesture_;
-      manager_->OnUserGestureConsumed(web_contents(),
-                                      last_user_gesture_timestamp_);
+      nav_event.is_user_initiated = true;
+      if (has_user_gesture_) {
+        manager_->OnUserGestureConsumed(web_contents(),
+                                        last_user_gesture_timestamp_);
+        has_user_gesture_ = false;

[Nathan Parker, 2016/12/20 01:01:33]

So this consumes the user gesture only if there really was one... correct?  Just
trying to make sure I understand it.

[Jialiu Lin, 2016/12/20 02:07:51]

Yes. That's correct.

+      }
     }
-    has_user_gesture_ = false;
   }
 
   // All the other fields are reconstructed based on current content of
   // navigation_handle.
   nav_event.frame_id = navigation_handle->GetFrameTreeNodeId();
 
   // If there was a URL previously committed in the current RenderFrameHost,
   // set it as the source url of this navigation. Otherwise, this is the
   // first url going to commit in this frame. We set navigation_handle's URL as
   // the source url.
@@ skipping 94 matching lines @@
                                             last_user_gesture_timestamp_);
 }
 
 void SafeBrowsingNavigationObserver::WebContentsDestroyed() {
   manager_->OnWebContentDestroyed(web_contents());
   web_contents()->RemoveUserData(kWebContentsUserDataKey);
   // web_contents is null after this function.
 }
 
 }  // namespace safe_browsing