Prerender: Set Prerendering State for Sub-Frame Navigations

https://chromium-review.googlesource.com/c/chromium/src/+/2583677 only
set the prerendering state for main-frame navigation.
This CL shares parents' prerendering states with their children, so that
sub-frames can also know the correct prerendering state.

Bug: 1142658
Change-Id: I70552d4dc6380f91536e062ad2ea3ec8d0719b45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2603660Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842936}

content/browser/prerender/prerender_browsertest.cc

@@ -8,6 +8,7 @@
 #include "base/thread_annotations.h"
 #include "content/browser/prerender/prerender_host.h"
 #include "content/browser/prerender/prerender_host_registry.h"
+#include "content/browser/renderer_host/frame_tree_node.h"
 #include "content/browser/renderer_host/render_frame_host_impl.h"
 #include "content/browser/storage_partition_impl.h"
 #include "content/public/browser/browser_context.h"
@@ -133,6 +134,49 @@ class PrerenderBrowserTest : public ContentBrowserTest,
 
   bool IsActivationDisabled() const { return GetParam(); }
 
+  void TestRenderFrameHostPrerenderingState(const GURL& prerender_url) {
+    const GURL kInitialUrl = GetUrl("/prerender/add_prerender.html");
+
+    // Navigate to an initial page.
+    ASSERT_TRUE(NavigateToURL(shell(), kInitialUrl));
+
+    // The initial page should not be for prerendering.
+    RenderFrameHostImpl* initiator_render_frame_host =
+        static_cast<RenderFrameHostImpl*>(
+            shell()->web_contents()->GetMainFrame());
+    EXPECT_FALSE(initiator_render_frame_host->IsPrerendering());
+    // Start a prerender.
+    AddPrerender(prerender_url);
+    PrerenderHostRegistry& registry = GetPrerenderHostRegistry();
+    PrerenderHost* prerender_host =
+        registry.FindHostByUrlForTesting(prerender_url);
+
+    // Verify all RenderFrameHostImpl in the prerendered page know the
+    // prerendering state.
+    RenderFrameHostImpl* prerendered_render_frame_host =
+        prerender_host->GetPrerenderedMainFrameHostForTesting();
+    std::vector<RenderFrameHost*> frames =
+        prerendered_render_frame_host->GetFramesInSubtree();
+    for (auto* frame : frames) {
+      auto* rfhi = static_cast<RenderFrameHostImpl*>(frame);
+      EXPECT_TRUE(rfhi->IsPrerendering());
+    }
+
+    // Activate the prerendered page.
+    NavigateWithLocation(prerender_url);
+
+    // The activated page should no longer be in the prerendering state.
+    RenderFrameHostImpl* navigated_render_frame_host =
+        static_cast<RenderFrameHostImpl*>(
+            shell()->web_contents()->GetMainFrame());
+    // The new page shouldn't be in the prerendering state.
+    frames = navigated_render_frame_host->GetFramesInSubtree();
+    for (auto* frame : frames) {
+      auto* rfhi = static_cast<RenderFrameHostImpl*>(frame);
+      EXPECT_FALSE(rfhi->IsPrerendering());
+    }
+  }
+
  private:
   net::test_server::EmbeddedTestServer ssl_server_{
       net::test_server::EmbeddedTestServer::TYPE_HTTPS};
@@ -274,56 +318,6 @@ IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, LinkRelPrerender_Duplicate) {
   }
 }
 
-IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, InformedRenderFrameHost) {
-  const GURL kInitialUrl = GetUrl("/prerender/add_prerender.html");
-  const GURL kPrerenderingUrl = GetUrl("/empty.html");
-
-  // Navigate to an initial page.
-  ASSERT_TRUE(NavigateToURL(shell(), kInitialUrl));
-  ASSERT_EQ(shell()->web_contents()->GetURL(), kInitialUrl);
-
-  // The initial page should not be for prerendering.
-  RenderFrameHostImpl* initiator_render_frame_host =
-      static_cast<RenderFrameHostImpl*>(
-          shell()->web_contents()->GetMainFrame());
-  EXPECT_FALSE(initiator_render_frame_host->IsPrerendering());
-
-  // Add <link rel=prerender> that will prerender `kPrerenderingUrl`.
-  ASSERT_EQ(GetRequestCount(kPrerenderingUrl), 0);
-  AddPrerender(kPrerenderingUrl);
-  EXPECT_EQ(GetRequestCount(kPrerenderingUrl), 1);
-
-  // A prerender host for the URL should be registered.
-  PrerenderHostRegistry& registry = GetPrerenderHostRegistry();
-  PrerenderHost* prerender_host =
-      registry.FindHostByUrlForTesting(kPrerenderingUrl);
-  EXPECT_NE(prerender_host, nullptr);
-
-  // Verify the corresponding RenderFrameHostImpl knows the prerendering state.
-  RenderFrameHostImpl* prerendered_render_frame_host =
-      prerender_host->GetPrerenderedMainFrameHostForTesting();
-  EXPECT_TRUE(prerendered_render_frame_host->IsPrerendering());
-
-  // Activate the prerendered page.
-  NavigateWithLocation(kPrerenderingUrl);
-  if (IsActivationDisabled()) {
-    // Activation is disabled, so the page should newly be rendered instead
-    // of the prerendered page.
-    RenderFrameHostImpl* new_render_frame_host =
-        static_cast<RenderFrameHostImpl*>(
-            shell()->web_contents()->GetMainFrame());
-    EXPECT_NE(prerendered_render_frame_host, new_render_frame_host);
-    // The new page shouldn't be in the prerendering state.
-    EXPECT_FALSE(new_render_frame_host->IsPrerendering());
-  } else {
-    // The prerendered page is activated. The page should no longer be in
-    // the prerendering state.
-    ASSERT_EQ(prerendered_render_frame_host,
-              shell()->web_contents()->GetMainFrame());
-    EXPECT_FALSE(prerendered_render_frame_host->IsPrerendering());
-  }
-}
-
 // Makes sure that activations on navigations for iframes don't happen.
 IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, Activation_iFrame) {
   const GURL kInitialUrl = GetUrl("/prerender/add_prerender.html");
@@ -410,6 +404,18 @@ IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, HistoryAfterActivation) {
   EXPECT_EQ(shell()->web_contents()->GetLastCommittedURL(), kInitialUrl);
 }
 
+// Tests that all RenderFrameHostImpls in the prerendering page know the
+// prerendering state.
+IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, PrerenderIframe) {
+  TestRenderFrameHostPrerenderingState(GetUrl("/page_with_iframe.html"));
+}
+
+// Blank <iframe> is a special case. Tests that the blank iframe knows the
+// prerendering state as well.
+IN_PROC_BROWSER_TEST_P(PrerenderBrowserTest, PrerenderBlankIframe) {
+  TestRenderFrameHostPrerenderingState(GetUrl("/page_with_blank_iframe.html"));
+}
+
 // TODO(https://crbug.com/1132746): Test canceling prerendering.
 
 // TODO(https://crbug.com/1132746): Test prerendering for 404 page, redirection,

content/browser/renderer_host/navigation_request.cc

@@ -766,6 +766,12 @@ std::unique_ptr<NavigationRequest> NavigationRequest::CreateBrowserInitiated(
     }
   }
 
+  // The prerendering state of a sub-frame is decided by its parent.
+  if (base::FeatureList::IsEnabled(blink::features::kPrerender2) &&
+      frame_tree_node->parent()) {
+    is_prerendering = frame_tree_node->parent()->IsPrerendering();
+  }
+
   std::unique_ptr<NavigationRequest> navigation_request(new NavigationRequest(
       frame_tree_node, std::move(common_params), std::move(navigation_params),
       std::move(commit_params), browser_initiated,
@@ -880,6 +886,13 @@ std::unique_ptr<NavigationRequest> NavigationRequest::CreateRendererInitiated(
   int initiator_process_id =
       frame_tree_node->current_frame_host()->GetProcess()->GetID();
 
+  // For sub-frame navigations, inherit the prerendering state from the parent.
+  bool is_prerendering = false;
+  if (base::FeatureList::IsEnabled(blink::features::kPrerender2) &&
+      frame_tree_node->parent()) {
+    is_prerendering = frame_tree_node->parent()->IsPrerendering();
+  }
+
   // `was_opener_suppressed` can be true for renderer initiated navigations, but
   // only in cases which get routed through `CreateBrowserInitiated()` instead.
   std::unique_ptr<NavigationRequest> navigation_request(new NavigationRequest(
@@ -888,8 +901,9 @@ std::unique_ptr<NavigationRequest> NavigationRequest::CreateRendererInitiated(
       false,  // browser_initiated
       true,   // from_begin_navigation
       false,  // is_for_commit
-      false,  // is_prerendering
-      nullptr, entry,
+      is_prerendering,
+      nullptr,  // frame_entry
+      entry,
       nullptr,  // navigation_ui_data
       std::move(navigation_client), std::move(navigation_initiator),
       nullptr,  // rfh_restored_from_back_forward_cache

content/browser/renderer_host/render_frame_host_impl.cc

@@ -7812,6 +7812,9 @@ void RenderFrameHostImpl::OnPrerenderedPageActivated() {
   DCHECK(is_prerendering_);
   is_prerendering_ = false;
 
+  for (auto& child : children_)
+    child->current_frame_host()->OnPrerenderedPageActivated();
+
   // TODO(https://crbug.com/1132752): Inform `broker_` that the prerendered
   // frame is activated.
 }
@@ -8781,6 +8784,14 @@ bool RenderFrameHostImpl::DidCommitNavigationInternal(
     // create one in order to properly issue DidFinishNavigation calls to
     // WebContentsObservers.
     DCHECK(is_initial_empty_commit || is_same_document_navigation);
+
+    // Handle src-less <iframe> for prerendering.
+    // This is a special case that does not go through CommitNavigation path.
+    if (base::FeatureList::IsEnabled(blink::features::kPrerender2) &&
+        is_initial_empty_commit && !is_main_frame()) {
+      is_prerendering_ = parent_->IsPrerendering();
+    }
+
     // TODO(https://crbug.com/1131832): Do not use |params| to get the values,
     // depend on values known at commit time instead.
     navigation_request = CreateNavigationRequestForCommit(