[Prerender] Part 1: Delete old style prerender code.

This is to be submitted once all changes for Bug 898955 have landed.

Bug: 1106294
Change-Id: I1beb9f425c4f7774831a155be38483ae9b9aed4a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2302010
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792073}

chrome/browser/android/tab_android.cc

@@ -374,14 +374,6 @@ TabAndroid::TabLoadStatus TabAndroid::LoadUrl(
   if (gurl.is_empty())
     return PAGE_LOAD_FAILED;
 
-  // If the page was prerendered, use it.
-  // Note in incognito mode, we don't have a PrerenderManager.
-  bool loaded;
-  if (prerender::PrerenderManager::MaybeUsePrerenderedPage(
-          GetProfile(), web_contents(), gurl, &loaded)) {
-    return loaded ? FULL_PRERENDERED_PAGE_LOAD : PARTIAL_PRERENDERED_PAGE_LOAD;
-  }
-
   GURL fixed_url(
       url_formatter::FixupURL(gurl.possibly_invalid_spec(), std::string()));
   if (!fixed_url.is_valid())

chrome/browser/android/tab_web_contents_delegate_android.cc

@@ -384,17 +384,6 @@ WebContents* TabWebContentsDelegateAndroid::OpenURLFromTab(
   }
 
   if (disposition == WindowOpenDisposition::CURRENT_TAB) {
-    // Only prerender for a current-tab navigation to avoid session storage
-    // namespace issues.
-    prerender::PrerenderManager::Params prerender_params(
-        popup_delegate->nav_params(), source);
-    prerender::PrerenderManager* prerender_manager =
-        prerender::PrerenderManagerFactory::GetForBrowserContext(profile);
-    if (prerender_manager && prerender_manager->MaybeUsePrerenderedPage(
-                                 params.url, &prerender_params)) {
-      return prerender_params.replaced_contents;
-    }
-
     // Ask the parent to handle in-place opening.
     return WebContentsDelegateAndroid::OpenURLFromTab(source, params);
   }

chrome/browser/prerender/prerender_contents.cc

@@ -135,8 +135,7 @@ PrerenderContents::PrerenderContents(
     const content::Referrer& referrer,
     const base::Optional<url::Origin>& initiator_origin,
     Origin origin)
-    : prerender_mode_(
-          prerender::mojom::PrerenderMode::kDeprecatedFullPrerender),
+    : prerender_mode_(prerender::mojom::PrerenderMode::kNoPrerender),
       prerendering_has_started_(false),
       prerender_manager_(prerender_manager),
       prerender_url_(url),

chrome/browser/prerender/prerender_manager.h

@@ -36,8 +36,6 @@ class ListValue;
 class TickClock;
 }  // namespace base
 
-struct NavigateParams;
-
 namespace chrome_browser_net {
 enum class NetworkPredictionStatus;
 }
@@ -76,9 +74,6 @@ class PrerenderManager : public content::RenderProcessHostObserver,
                          public KeyedService {
  public:
   enum PrerenderManagerMode {
-    // Deprecated: Enables all types of prerendering for any origin.
-    DEPRECATED_PRERENDER_MODE_ENABLED,
-
     // For each request to prerender performs a NoStatePrefetch for the same URL
     // instead.
     PRERENDER_MODE_NOSTATE_PREFETCH,
@@ -96,22 +91,6 @@ class PrerenderManager : public content::RenderProcessHostObserver,
     CLEAR_MAX = 0x1 << 2
   };
 
-  // If |url| matches a valid prerendered page in one of the contents,
-  // try to swap it and merge browsing histories.
-  //
-  // Returns true if a prerendered page is swapped in. When this happens, the
-  // PrerenderManager has already swapped out |contents_being_navigated| with
-  // |replaced_contents| in the WebContents container [e.g. TabStripModel on
-  // desktop]. |loaded| is set to true if the page finished loading.
-  //
-  // Returns false if nothing is swapped.
-  //
-  // |loaded| cannot be null.
-  static bool MaybeUsePrerenderedPage(Profile* profile,
-                                      content::WebContents* web_contents,
-                                      const GURL& url,
-                                      bool* loaded);
-
   // Owned by a Profile object for the lifetime of the profile.
   explicit PrerenderManager(Profile* profile);
   ~PrerenderManager() override;
@@ -183,36 +162,6 @@ class PrerenderManager : public content::RenderProcessHostObserver,
   // Cancels all active prerenders.
   void CancelAllPrerenders();
 
-  // Wraps input and output parameters to MaybeUsePrerenderedPage.
-  struct Params {
-    Params(NavigateParams* params,
-           content::WebContents* contents_being_navigated);
-    Params(bool uses_post,
-           const std::string& extra_headers,
-           bool should_replace_current_entry,
-           content::WebContents* contents_being_navigated);
-
-    // Input parameters.
-    const bool uses_post;
-    const std::string extra_headers;
-    const bool should_replace_current_entry;
-    content::WebContents* const contents_being_navigated;
-
-    // Output parameters.
-    content::WebContents* replaced_contents = nullptr;
-  };
-
-  // If |url| matches a valid prerendered page and |params| are compatible, try
-  // to swap it and merge browsing histories.
-  //
-  // Returns true if a prerendered page is swapped in. When this happens, the
-  // PrerenderManager has already swapped out |contents_being_navigated| with
-  // |replaced_contents| in the WebContents container [e.g. TabStripModel on
-  // desktop].
-  //
-  // Returns false if nothing is swapped.
-  bool MaybeUsePrerenderedPage(const GURL& url, Params* params);
-
   // Moves a PrerenderContents to the pending delete list from the list of
   // active prerenders when prerendering should be cancelled.
   virtual void MoveEntryToPendingDelete(PrerenderContents* entry,

chrome/browser/ui/browser_navigator.cc

@@ -457,22 +457,6 @@ std::unique_ptr<content::WebContents> CreateTargetContents(
   return target_contents;
 }
 
-// If a prerendered page exists for |url|, then replace
-// params.contents_being_navigated with it. When this occurs, the new page is
-// stored in params.replaced_contents.
-// This method updates the underlying storage mechanism as well. e.g. On
-// Desktop, |contents_being_navigated| is replaced in the tabstrip by
-// |replaced_contents|.
-bool SwapInPrerender(const GURL& url,
-                     prerender::PrerenderManager::Params* params) {
-  Profile* profile = Profile::FromBrowserContext(
-      params->contents_being_navigated->GetBrowserContext());
-  prerender::PrerenderManager* prerender_manager =
-      prerender::PrerenderManagerFactory::GetForBrowserContext(profile);
-  return prerender_manager &&
-         prerender_manager->MaybeUsePrerenderedPage(url, params);
-}
-
 }  // namespace
 
 void Navigate(NavigateParams* params) {
@@ -622,9 +606,6 @@ void Navigate(NavigateParams* params) {
       params->transition & ui::PAGE_TRANSITION_FROM_ADDRESS_BAR ||
       !ui::PageTransitionIsWebTriggerable(params->transition);
 
-  // Did we use a prerender?
-  bool swapped_in_prerender = false;
-
   // If no target WebContents was specified (and we didn't seek and find a
   // singleton), we need to construct one if we are supposed to target a new
   // tab.
@@ -638,26 +619,15 @@ void Navigate(NavigateParams* params) {
       // same as the source.
       DCHECK(params->source_contents);
       contents_to_navigate_or_insert = params->source_contents;
-
-      prerender::PrerenderManager::Params prerender_params(
-          params, params->source_contents);
-
-      // Prerender can only swap in CURRENT_TAB navigations; others have
-      // different sessionStorage namespaces.
-      swapped_in_prerender = SwapInPrerender(params->url, &prerender_params);
-      if (swapped_in_prerender)
-        contents_to_navigate_or_insert = prerender_params.replaced_contents;
     }
 
-    if (!swapped_in_prerender) {
-      // Try to handle non-navigational URLs that popup dialogs and such, these
-      // should not actually navigate.
-      if (!HandleNonNavigationAboutURL(params->url)) {
-        // Perform the actual navigation, tracking whether it came from the
-        // renderer.
+    // Try to handle non-navigational URLs that popup dialogs and such, these
+    // should not actually navigate.
+    if (!HandleNonNavigationAboutURL(params->url)) {
+      // Perform the actual navigation, tracking whether it came from the
+      // renderer.
 
-        LoadURLInContents(contents_to_navigate_or_insert, params->url, params);
-      }
+      LoadURLInContents(contents_to_navigate_or_insert, params->url, params);
     }
   } else {
     // |contents_to_navigate_or_insert| was specified non-NULL, and so we assume
@@ -674,9 +644,7 @@ void Navigate(NavigateParams* params) {
       (params->tabstrip_add_types & TabStripModel::ADD_INHERIT_OPENER))
     params->source_contents->Focus();
 
-  if (params->source_contents == contents_to_navigate_or_insert ||
-      (swapped_in_prerender &&
-       params->disposition == WindowOpenDisposition::CURRENT_TAB)) {
+  if (params->source_contents == contents_to_navigate_or_insert) {
     // The navigation occurred in the source tab.
     params->browser->UpdateUIForNavigationInTab(
         contents_to_navigate_or_insert, params->transition,

components/prerender/common/prerender_types.mojom

@@ -8,9 +8,6 @@ enum PrerenderMode {
   // Neither prefetch nor prerender.
   kNoPrerender = 0,
 
-  // Only used in tests. Can be removed after http://crbug.com/898955 is fixed.
-  kDeprecatedFullPrerender = 1,
-
   // Prefetch some network resources to warm up the cache.
   kPrefetchOnly = 2,
 };