fix: improve prefetching conformance for the foreground parser

Dispatches link=rel preloads before they're added to the page,
which makes prefetching behaviour more similar to the
background parser.

Bug: 901056
Change-Id: Ia60c5c241c96860fb50218d4eca71eedb4ec91b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2540449
Commit-Queue: Richard Townsend <richard.townsend@arm.com>
Reviewed-by: Mason Freed <masonfreed@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828736}

third_party/blink/renderer/core/html/parser/html_document_parser.cc

@@ -131,7 +131,9 @@ class HTMLDocumentParserState
         meta_csp_state_(MetaCSPTokenState::kNotSeen),
         mode_(mode),
         end_if_delayed_forbidden_(0),
-        should_complete_(0) {}
+        should_complete_(0),
+        needs_viewport_update_(false),
+        needs_link_header_dispatch_(true) {}
 
   void Trace(Visitor* v) const {}
 
@@ -153,6 +155,17 @@ class HTMLDocumentParserState
     }
   }
 
+  bool NeedsLinkHeaderPreloadsDispatch() const {
+    return needs_link_header_dispatch_;
+  }
+  bool NeedsViewportUpdate() const { return needs_viewport_update_; }
+  void SetNeedsViewportUpdate() { needs_viewport_update_ = true; }
+  void DispatchedLinkHeaderPreloads() { needs_link_header_dispatch_ = false; }
+  void UpdatedViewport() {
+    needs_viewport_update_ = false;
+    needs_link_header_dispatch_ = true;
+  }
+
   bool ShouldEndIfDelayed() const { return end_if_delayed_forbidden_ == 0; }
   bool ShouldComplete() const {
     return should_complete_ || GetMode() != kAllowDeferredParsing;
@@ -196,6 +209,8 @@ class HTMLDocumentParserState
   ParserSynchronizationPolicy mode_;
   int end_if_delayed_forbidden_;
   int should_complete_;
+  bool needs_viewport_update_;
+  bool needs_link_header_dispatch_;
 };
 
 class EndIfDelayedForbiddenScope {
@@ -1232,12 +1247,6 @@ void HTMLDocumentParser::Append(const String& input_source) {
     return;
   }
   if (preload_scanner_) {
-    if (input_.Current().IsEmpty() && !IsPaused()) {
-      // We have parsed until the end of the current input and so are now
-      // moving ahead of the preload scanner. Clear the scanner so we know to
-      // scan starting from the current input point if we block again.
-      preload_scanner_.reset();
-    } else {
       preload_scanner_->AppendToEnd(source);
       if (preloader_) {
         if (!task_runner_state_->IsSynchronous() || IsPaused()) {
@@ -1247,7 +1256,6 @@ void HTMLDocumentParser::Append(const String& input_source) {
           ScanAndPreload(preload_scanner_.get());
         }
       }
-    }
   }
 
   input_.AppendToEnd(source);
@@ -1672,8 +1680,42 @@ void HTMLDocumentParser::ScanAndPreload(HTMLPreloadScanner* scanner) {
   TRACE_EVENT0("blink", "HTMLDocumentParser::ScanAndPreload");
   DCHECK(preloader_);
   bool seen_csp_meta_tag = false;
-  PreloadRequestStream requests = scanner->Scan(
-      GetDocument()->ValidBaseElementURL(), nullptr, seen_csp_meta_tag);
+  base::Optional<ViewportDescription> viewport_description;
+  PreloadRequestStream requests =
+      scanner->Scan(GetDocument()->ValidBaseElementURL(), &viewport_description,
+                    seen_csp_meta_tag);
+  if (viewport_description.has_value()) {
+    task_runner_state_->SetNeedsViewportUpdate();
+  }
+  // Make sure that the viewport is up-to-date, so that the correct viewport
+  // dimensions will be fed to the background parser and preload scanner.
+  if (GetDocument()->Loader() &&
+      task_runner_state_->GetMode() == kAllowDeferredParsing) {
+    if (task_runner_state_->NeedsViewportUpdate()) {
+      GetDocument()->GetStyleEngine().UpdateViewport();
+      task_runner_state_->UpdatedViewport();
+    }
+    if (task_runner_state_->NeedsLinkHeaderPreloadsDispatch()) {
+      if (GetDocument()->Loader()->GetPrefetchedSignedExchangeManager()) {
+        TRACE_EVENT0("blink",
+                     "HTMLDocumentParser::DispatchSignedExchangeManager");
+        // Link header preloads for prefetched signed exchanges won't be started
+        // until StartPrefetchedLinkHeaderPreloads() is called. See the header
+        // comment of PrefetchedSignedExchangeManager.
+        GetDocument()
+            ->Loader()
+            ->GetPrefetchedSignedExchangeManager()
+            ->StartPrefetchedLinkHeaderPreloads();
+      } else {
+        TRACE_EVENT0("blink", "HTMLDocumentParser::DispatchLinkHeaderPreloads");
+        GetDocument()->Loader()->DispatchLinkHeaderPreloads(
+            base::OptionalOrNullptr(viewport_description),
+            PreloadHelper::kOnlyLoadMedia);
+      }
+      task_runner_state_->DispatchedLinkHeaderPreloads();
+    }
+  }
+
   task_runner_state_->SetSeenCSPMetaTag(seen_csp_meta_tag);
   for (auto& request : requests) {
     queued_preloads_.push_back(std::move(request));

third_party/blink/renderer/core/html/parser/html_document_parser_test.cc

@@ -151,7 +151,8 @@ TEST_P(HTMLDocumentParserTest, AppendNoPrefetch) {
   // The bytes are forwarded to the tokenizer.
   HTMLParserScriptRunnerHost* script_runner_host =
       parser->AsHTMLParserScriptRunnerHostForTesting();
-  EXPECT_FALSE(script_runner_host->HasPreloadScanner());
+  EXPECT_EQ(script_runner_host->HasPreloadScanner(),
+            testing::get<0>(GetParam()) == kAllowDeferredParsing);
   EXPECT_EQ(HTMLTokenizer::kTagNameState, parser->Tokenizer()->GetState());
   // Cancel any pending work to make sure that RuntimeFeatures DCHECKs do not
   // fire.

third_party/blink/web_tests/FlagExpectations/enable-blink-features=ForceSynchronousHTMLParsing

@@ -4,13 +4,8 @@
 # File containing known test issues under the synchronous, budgeted foreground HTML parser
 # Ordered from most to least serious.
 
-# This set of test crashes comes because response_document_ is unexpectedly nullptr in DCHECK builds.
-### external/wpt/service-workers/service-worker/
-crbug.com/901056 external/wpt/service-workers/service-worker/xhr-response-url.https.html [ Crash ]
-
 ### virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/
 crbug.com/901056 virtual/plz-dedicated-worker/external/wpt/service-workers/service-worker/xhr-response-url.https.html [ Crash ]
-
 #
 # Timeouts
 #
@@ -18,29 +13,13 @@ crbug.com/901056 virtual/plz-dedicated-worker/external/wpt/service-workers/servi
 ### http/tests/loading/sxg/
 crbug.com/901056 http/tests/loading/sxg/sxg-subresource-origin-trial.https.html [ Timeout Failure ]
 
-### http/tests/preload/
-crbug.com/901056 http/tests/preload/meta-viewport-link-headers-imagesrcset.html [ Timeout ]
-
 ### http/tests/inspector-protocol/issues/
 crbug.com/901056 http/tests/inspector-protocol/issues/mixed-content-issue-creation-js-within-oopif.js [ Timeout ]
 
-### virtual/gpu/fast/canvas/
-crbug.com/901056 virtual/gpu/fast/canvas/canvas-drawImage-live-video.html [ Timeout ]
-
-### external/wpt/signed-exchange/subresource/
-crbug.com/901056 external/wpt/signed-exchange/subresource/sxg-subresource.tentative.html [ Timeout ]
-
-### http/tests/inspector-protocol/issues/
-crbug.com/901056 http/tests/inspector-protocol/issues/mixed-content-issue-creation-css.js [ Timeout ]
-crbug.com/901056 http/tests/inspector-protocol/issues/mixed-content-issue-creation-js-within-iframe.js [ Timeout ]
-crbug.com/901056 http/tests/inspector-protocol/issues/mixed-content-issue-creation-js.js [ Timeout ]
-
 #
 # Harness failures
 #
 # Most of these failures are due to layout viewport issues
-### external/wpt/preload/
-crbug.com/901056 external/wpt/preload/link-header-preload-imagesrcset.html [ Failure ]
 
 ### http/tests/preload/
 # This one happens because HTMLPreloadSanner discards all scanned preloads whenever it sees a <meta> CSP token.
@@ -57,28 +36,12 @@ crbug.com/901056 media/controls/rotated-video-has-right-panel-width.html [ Failu
 
 ### virtual/plz-dedicated-worker/external/wpt/resource-timing/
 crbug.com/901056 virtual/plz-dedicated-worker/external/wpt/resource-timing/nested-context-navigations-object.html [ Failure ]
-
-#
-# Image failures
-#
-### css1/pseudo/
-# Line-wrapping is slightly different
-crbug.com/901056 css1/pseudo/pseudo_elements_in_selectors.html [ Failure ]
-
-### fast/hidpi/
-# Document width is different
-crbug.com/901056 fast/hidpi/image-srcset-png-canvas.html [ Failure ]
-
 #
 # Text failures
 #
 ### fast/block/float
 crbug.com/901056 fast/block/float/4145535Crash.html [ Failure Pass ]
 
-### fast/preloader/
-# Two new subtests fail (investigation required)
-crbug.com/901056 fast/preloader/is-preloaded-after-load.html [ Failure ]
-
 ### http/tests/devtools/console
 # An extra "VM" is printed in front of the page name.
 crbug.com/901056 http/tests/devtools/console/console-uncaught-exception.js [ Failure ]
@@ -105,10 +68,6 @@ crbug.com/901056 http/tests/security/contentSecurityPolicy/nonces/scriptnonce-re
 # Probably a viewport sizing issue (investigation needed).
 crbug.com/901056 paint/invalidation/overflow/resize-child-within-overflow.html [ Failure ]
 
-### tables/mozilla_expected_failures/bugs/
-# Blocked access message no longer emitted (investigation needed).
-crbug.com/901056 tables/mozilla_expected_failures/bugs/bug128876.html [ Failure ]
-
 ### virtual/conditional-appcache-delay/http/tests/loading/appcache-delay/
 # WontFix (AppCache will be removed at some point.)
 crbug.com/901056 virtual/conditional-appcache-delay/http/tests/loading/appcache-delay/appcache-loads-subresource.html [ Failure ]

third_party/blink/web_tests/TestExpectations

@@ -74,20 +74,12 @@ external/wpt/css/compositing/root-element-background-transparency.html [ Failure
 # ====== Synchronous, budgeted HTML parser tests from here ======
 
 ### virtual/synchronous_html_parser/http/tests/preload/
+# An extra line ("linear_memory_inspector") appears in the output in some cases.
+crbug.com/901056 http/tests/devtools/modules-load-source.js [ Failure Pass ]
+# Extra line info appears in the output in some cases.
+crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/content-security-policy-issue-creation-img.js [ Failure Pass ]
 crbug.com/901056 virtual/synchronous_html_parser/http/tests/preload/meta-csp.html [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/preload/meta-viewport-device-width-link-headers.html [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/preload/meta-viewport-link-headers-imagesrcset.html [ Timeout Failure ]
 crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/mixed-content-issue-creation-js-within-oopif.js [ Timeout ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/mixed-content-issue-creation-css.js [ Timeout ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/mixed-content-issue-creation-js-within-iframe.js [ Timeout ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/mixed-content-issue-creation-js.js [ Timeout ]
-# Minor issues, need rebaselining
-crbug.com/901056 virtual/synchronous_html_parser/fast/css/focus-display-block-inline.html [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/fast/css/fontfaceset-multiple-families.html [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/content-security-policy-issue-creation-img.js [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/network/initiator-minified.js [ Failure ]
-crbug.com/901056 virtual/synchronous_html_parser/external/wpt/signed-exchange/subresource/sxg-subresource.tentative.html [ Failure Timeout ]
-
 # ====== Site Isolation failures from here ======
 # See also third_party/blink/web_tests/virtual/not-site-per-process/README.md
 # Tests temporarily disabled with Site Isolation - uninvestigated bugs:

third_party/blink/web_tests/platform/linux/virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/content-security-policy-issue-creation-img-expected.txt

+Verifies that CSP issue is created from a page with image source violation.
+
+Inspector issue: {
+    issue : {
+        code : ContentSecurityPolicyIssue
+        details : {
+            contentSecurityPolicyIssueDetails : {
+                blockedURL : https://thirdparty.test/network/resources/to-be-blocked.jpg
+                contentSecurityPolicyViolationType : kURLViolation
+                isReportOnly : false
+                sourceCodeLocation : {
+                    columnNumber : 0
+                    lineNumber : 8
+                    url : https://devtools.test:8443/inspector-protocol/resources/content-security-policy-issue-image.php
+                }
+                violatedDirective : img-src
+            }
+        }
+    }
+}
+