prerender: Expose activation result to DevTools

This CL introduces activated status in PrerenderHost to DevTools, and
adds a related inspector protocol test.

Bug: 1249776
Change-Id: Iaa9eebc1d107271e53194d1fc49033a5b858bfe3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3479000
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Huanpo Lin <robertlin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#987333}

content/browser/devtools/devtools_instrumentation.cc

@@ -301,6 +301,12 @@ void BackForwardCacheNotUsed(
                    nav_request, result, tree_result);
 }
 
+void DidActivatePrerender(const NavigationRequest& nav_request) {
+  FrameTreeNode* ftn = nav_request.frame_tree_node();
+  DispatchToAgents(ftn, &protocol::PageHandler::DidActivatePrerender,
+                   nav_request);
+}
+
 namespace {
 
 protocol::String BuildBlockedByResponseReason(

content/browser/devtools/devtools_instrumentation.h

@@ -160,6 +160,8 @@ void BackForwardCacheNotUsed(
     const BackForwardCacheCanStoreDocumentResult* result,
     const BackForwardCacheCanStoreTreeResult* tree_result);
 
+void DidActivatePrerender(const NavigationRequest& nav_request);
+
 void OnSignedExchangeReceived(
     FrameTreeNode* frame_tree_node,
     absl::optional<const base::UnguessableToken> devtools_navigation_token,

content/browser/devtools/protocol/page_handler.cc

@@ -1867,6 +1867,17 @@ void PageHandler::BackForwardCacheNotUsed(
                                      std::move(explanation_tree));
 }
 
+void PageHandler::DidActivatePrerender(const NavigationRequest& nav_request) {
+  if (!enabled_)
+    return;
+  FrameTreeNode* ftn = nav_request.frame_tree_node();
+  std::string initiating_frame_id = ftn->devtools_frame_token().ToString();
+  const GURL& prerendering_url = nav_request.common_params().url;
+  frontend_->PrerenderAttemptCompleted(
+      initiating_frame_id, prerendering_url.spec(),
+      Page::PrerenderFinalStatusEnum::Activated);
+}
+
 bool PageHandler::ShouldBypassCSP() {
   return enabled_ && bypass_csp_;
 }

content/browser/devtools/protocol/page_handler.h

@@ -108,6 +108,8 @@ class PageHandler : public DevToolsDomainHandler,
       const BackForwardCacheCanStoreDocumentResult* result,
       const BackForwardCacheCanStoreTreeResult* tree_result);
 
+  void DidActivatePrerender(const NavigationRequest& nav_request);
+
   Response Enable() override;
   Response Disable() override;
 

content/browser/devtools/protocol_config.json

@@ -71,7 +71,7 @@
                 "include": ["enable", "disable", "reload", "navigate", "stopLoading", "getNavigationHistory", "navigateToHistoryEntry", "resetNavigationHistory", "captureScreenshot",
                     "startScreencast", "stopScreencast", "screencastFrameAck", "handleJavaScriptDialog", "setColorPickerEnabled",
                     "bringToFront", "setDownloadBehavior", "getAppManifest", "crash", "close", "setWebLifecycleState", "captureSnapshot", "getInstallabilityErrors", "getManifestIcons", "setBypassCSP", "getAppId", "addCompilationCache"],
-                "include_events": ["colorPicked", "interstitialShown", "interstitialHidden", "javascriptDialogOpening", "javascriptDialogClosed", "downloadWillBegin", "downloadProgress", "screencastVisibilityChanged", "screencastFrame", "backForwardCacheNotUsed"],
+                "include_events": ["colorPicked", "interstitialShown", "interstitialHidden", "javascriptDialogOpening", "javascriptDialogClosed", "downloadWillBegin", "downloadProgress", "screencastVisibilityChanged", "screencastFrame", "backForwardCacheNotUsed", "prerenderAttemptCompleted"],
                 "async": ["captureScreenshot", "navigate", "getAppManifest", "reload", "captureSnapshot", "getInstallabilityErrors", "getManifestIcons", "getAppId"]
             },
             {

content/browser/prerender/prerender_host.cc

@@ -10,6 +10,7 @@
 #include "base/trace_event/common/trace_event_common.h"
 #include "base/trace_event/trace_conversion_helper.h"
 #include "base/trace_event/typed_macros.h"
+#include "content/browser/devtools/devtools_instrumentation.h"
 #include "content/browser/prerender/prerender_host_registry.h"
 #include "content/browser/prerender/prerender_metrics.h"
 #include "content/browser/renderer_host/frame_tree.h"
@@ -476,6 +477,7 @@ std::unique_ptr<StoredPage> PrerenderHost::Activate(
   // source ID.
   RecordFinalStatus(FinalStatus::kActivated, attributes_.initiator_ukm_id,
                     navigation_request.GetNextPageUkmSourceId());
+  devtools_instrumentation::DidActivatePrerender(navigation_request);
   return page;
 }
 

third_party/blink/public/devtools_protocol/browser_protocol.pdl

@@ -8262,6 +8262,19 @@ domain Page
       # Tree structure of reasons why the page could not be cached for each frame.
       optional BackForwardCacheNotRestoredExplanationTree notRestoredExplanationsTree
 
+  # List of FinalStatus reasons for Prerender2.
+  type PrerenderFinalStatus extends string
+    enum
+      Activated
+
+  # Fired when a prerender attempt is completed.
+  event prerenderAttemptCompleted
+    parameters
+      # The frame id of the frame initiating prerendering.
+      FrameId initiatingFrameId
+      string prerenderingUrl
+      PrerenderFinalStatus finalStatus
+
   event loadEventFired
     parameters
       Network.MonotonicTime timestamp

third_party/blink/web_tests/http/tests/inspector-protocol/prerender/report-prerender-final-status-expected.txt

@@ -0,0 +1,11 @@
+Test that prerender navigations report the final status
+{
+    method : Page.prerenderAttemptCompleted
+    params : {
+        finalStatus : Activated
+        initiatingFrameId : <string>
+        prerenderingUrl : http://127.0.0.1:8000/inspector-protocol/prerender/resources/empty.html
+    }
+    sessionId : <string>
+}
+

third_party/blink/web_tests/http/tests/inspector-protocol/prerender/report-prerender-final-status.js

@@ -0,0 +1,13 @@
+(async function(testRunner) {
+  const {page, session, dp} = await testRunner.startBlank(
+      `Test that prerender navigations report the final status`);
+  await dp.Page.enable();
+
+  // Navigate to speculation rules Prerender Page.
+  await page.navigate('resources/simple-prerender.html');
+  session.evaluate(`document.getElementById('link').click()`);
+  const statusReport = await dp.Page.oncePrerenderAttemptCompleted();
+  testRunner.log(statusReport, '', ['initiatingFrameId', 'sessionId']);
+
+  testRunner.completeTest();
+});

third_party/blink/web_tests/http/tests/inspector-protocol/prerender/resources/simple-prerender.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<head>
+<script type="speculationrules">
+{
+  "prerender":[
+    {"source": "list",
+     "urls": ["empty.html"]}
+  ]
+}
+</script>
+<title>Prerender Test</title>
+<!-- Make sure there is no zoom so that simulated clicks hit the right spot -->
+<meta name="viewport" content="width=device-width,minimum-scale=1">
+</head>
+<body><a href="empty.html" id="link">link</a></body>
+</html>