Fix double-use of getting a new page id in HTTPS Server Previews

GetNewPageId() is only called in one place now, GetOrCreateSLPInfo, and
this value is used for all restarted navigations, persisted by the Info.

Bug: 952523
Change-Id: Id9cdc8aead427c6cfefabd195db10ed251c6f787
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1567101Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#650642}

chrome/browser/previews/previews_lite_page_browsertest.cc

@@ -1455,6 +1455,15 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
   ui_test_utils::NavigateToURL(browser(), HttpsLitePageURL(kSuccess));
   VerifyPreviewLoaded();
 
+  PreviewsUITabHelper* ui_tab_helper =
+      PreviewsUITabHelper::FromWebContents(GetWebContents());
+  previews::PreviewsUserData* previews_data =
+      ui_tab_helper->previews_user_data();
+  // Grab the page id and session now because they may change after the reload.
+  uint64_t expected_page_id = previews_data->server_lite_page_info()->page_id;
+  std::string expected_session_key =
+      previews_data->server_lite_page_info()->drp_session_key;
+
   // Starting a new page load will send a pingback for the previous page load.
   GetWebContents()->GetController().Reload(content::ReloadType::NORMAL, false);
   pingback_client->WaitForPingback();
@@ -1470,20 +1479,8 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
   if (GetParam())
     return;
 
-  PreviewsUITabHelper* ui_tab_helper =
-      PreviewsUITabHelper::FromWebContents(GetWebContents());
-  previews::PreviewsUserData* previews_data =
-      ui_tab_helper->previews_user_data();
-
-  EXPECT_EQ(data->session_key(),
-            previews_data->server_lite_page_info()->drp_session_key);
-
-  // TODO(crbug.com/952523): The page id is being incremented for every
-  // restarted navigation. Fix and remove the early return.
-  return;
-
-  EXPECT_EQ(data->page_id().value(),
-            previews_data->server_lite_page_info()->page_id);
+  EXPECT_EQ(data->session_key(), expected_session_key);
+  EXPECT_EQ(data->page_id().value(), expected_page_id);
 }
 
 class PreviewsLitePageServerTimeoutBrowserTest

chrome/browser/previews/previews_lite_page_navigation_throttle.cc

@@ -116,26 +116,27 @@ class PreviewsWebContentsLifetimeHelper
     // restart. Note: This could be a navigation to the litepages server, or to
     // the original URL.
     if (restarted_navigation_url_ == handle->GetURL()) {
-      // Get a new page id.
-      PreviewsService* previews_service = PreviewsServiceFactory::GetForProfile(
-          Profile::FromBrowserContext(web_contents()->GetBrowserContext()));
-      PreviewsLitePageNavigationThrottleManager* manager =
-          previews_service->previews_lite_page_decider();
-      uint64_t page_id = manager->GeneratePageID();
+      if (!info_) {
+        // Create a new info_ if needed. This will use the previous page_id,
+        // which is desired.
+        PreviewsService* previews_service =
+            PreviewsServiceFactory::GetForProfile(Profile::FromBrowserContext(
+                web_contents()->GetBrowserContext()));
+        PreviewsLitePageNavigationThrottleManager* manager =
+            previews_service->previews_lite_page_decider();
+
+        info_ =
+            PreviewsLitePageNavigationThrottle::GetOrCreateServerLitePageInfo(
+                handle, manager)
+                ->Clone();
+      }
 
       // Create a new PreviewsUserData if needed.
       PreviewsUITabHelper* ui_tab_helper =
           PreviewsUITabHelper::FromWebContents(web_contents());
       previews::PreviewsUserData* previews_data =
-          ui_tab_helper->CreatePreviewsUserDataForNavigationHandle(handle,
-                                                                   page_id);
-
-      // Set the lite page state on the user data.
-      if (!info_) {
-        info_ =
-            std::make_unique<previews::PreviewsUserData::ServerLitePageInfo>();
-        info_->original_navigation_start = handle->NavigationStart();
-      }
+          ui_tab_helper->CreatePreviewsUserDataForNavigationHandle(
+              handle, info_->page_id);
       previews_data->set_server_lite_page_info(std::move(info_));
 
       // Reset member state.