Finish migrating LoadStylesheetIfNeeded logic to LinkLoader

Before this CL, ResourceRequest-based logic for all <link>s
that were not rel=manifest or rel=import resided in LinkStyle.
This CL pushes that logic down to LinkLoader for a better
separation of concerns.

R=yoav@yoav.ws

Bug: n/a
Change-Id: If1cc664b7de2ad54cf73d63a2e0d14943e698d04
Reviewed-on: https://chromium-review.googlesource.com/1087351
Commit-Queue: Dominic Farolino <domfarolino@gmail.com>
Reviewed-by: Yoav Weiss <yoav@yoav.ws>
Cr-Commit-Position: refs/heads/master@{#565317}

third_party/blink/renderer/core/html/html_link_element.cc

@@ -134,6 +134,14 @@ bool HTMLLinkElement::LoadLink(const LinkLoadParameters& params) {
                                 NetworkHintsInterfaceImpl());
 }
 
+void HTMLLinkElement::LoadStylesheet(const LinkLoadParameters& params,
+                                     const WTF::TextEncoding& charset,
+                                     FetchParameters::DeferOption defer_option,
+                                     ResourceClient* link_client) {
+  return link_loader_->LoadStylesheet(params, localName(), charset,
+                                      defer_option, GetDocument(), link_client);
+}
+
 LinkResource* HTMLLinkElement::LinkResourceToProcess() {
   if (!ShouldLoadLink()) {
     // If we shouldn't load the link, but the link is already of type

third_party/blink/renderer/core/html/html_link_element.h

@@ -38,6 +38,7 @@
 #include "third_party/blink/renderer/core/loader/link_loader.h"
 #include "third_party/blink/renderer/core/loader/link_loader_client.h"
 #include "third_party/blink/renderer/platform/bindings/trace_wrapper_member.h"
+#include "third_party/blink/renderer/platform/loader/fetch/fetch_parameters.h"
 
 namespace blink {
 
@@ -101,6 +102,10 @@ class CORE_EXPORT HTMLLinkElement final : public HTMLElement,
 
   // For LinkStyle
   bool LoadLink(const LinkLoadParameters&);
+  void LoadStylesheet(const LinkLoadParameters&,
+                      const WTF::TextEncoding&,
+                      FetchParameters::DeferOption,
+                      ResourceClient*);
   bool IsAlternate() const {
     return GetLinkStyle()->IsUnset() && rel_attribute_.IsAlternate();
   }

third_party/blink/renderer/core/html/link_style.cc

@@ -17,8 +17,6 @@
 #include "third_party/blink/renderer/core/loader/subresource_integrity_helper.h"
 #include "third_party/blink/renderer/platform/histogram.h"
 #include "third_party/blink/renderer/platform/loader/fetch/fetch_parameters.h"
-#include "third_party/blink/renderer/platform/loader/fetch/resource_loader_options.h"
-#include "third_party/blink/renderer/platform/loader/fetch/resource_request.h"
 #include "third_party/blink/renderer/platform/loader/subresource_integrity.h"
 #include "third_party/blink/renderer/platform/network/mime/content_type.h"
 #include "third_party/blink/renderer/platform/network/mime/mime_type_registry.h"
@@ -254,11 +252,11 @@ void LinkStyle::SetCrossOriginStylesheetStatus(CSSStyleSheet* sheet) {
 }
 
 LinkStyle::LoadReturnValue LinkStyle::LoadStylesheetIfNeeded(
-    const LinkLoadParameters& parameters,
+    const LinkLoadParameters& params,
     const WTF::TextEncoding& charset) {
   if (disabled_state_ == kDisabled || !owner_->RelAttribute().IsStyleSheet() ||
-      !StyleSheetTypeIsSupported(parameters.type) || !ShouldLoadResource() ||
-      !parameters.href.IsValid())
+      !StyleSheetTypeIsSupported(params.type) || !ShouldLoadResource() ||
+      !params.href.IsValid())
     return kNotNeeded;
 
   if (GetResource()) {
@@ -292,51 +290,18 @@ LinkStyle::LoadReturnValue LinkStyle::LoadStylesheetIfNeeded(
                   owner_->IsCreatedByParser();
   AddPendingSheet(blocking ? kBlocking : kNonBlocking);
 
-  // TODO(domfarolino): move the below fetching logic to
-  // LinkLoader::LoadStylesheet
-  ResourceRequest resource_request(GetDocument().CompleteURL(parameters.href));
-  ReferrerPolicy referrer_policy = owner_->GetReferrerPolicy();
-  if (referrer_policy != kReferrerPolicyDefault) {
-    resource_request.SetHTTPReferrer(SecurityPolicy::GenerateReferrer(
-        referrer_policy, parameters.href, GetDocument().OutgoingReferrer()));
-  }
-
-  if (RuntimeEnabledFeatures::PriorityHintsEnabled()) {
-    resource_request.SetFetchImportanceMode(
-        GetFetchImportanceAttributeValue(owner_->ImportanceValue()));
+  if (params.cross_origin != kCrossOriginAttributeNotSet) {
+    SetFetchFollowingCORS();
   }
 
-  ResourceLoaderOptions options;
-  options.initiator_info.name = owner_->localName();
-  FetchParameters params(resource_request, options);
-  params.SetCharset(charset);
-
   // Load stylesheets that are not needed for the layout immediately with low
   // priority.  When the link element is created by scripts, load the
   // stylesheets asynchronously but in high priority.
-  if (!media_query_matches || owner_->IsAlternate())
-    params.SetDefer(FetchParameters::kLazyLoad);
-
-  params.SetContentSecurityPolicyNonce(owner_->nonce());
+  FetchParameters::DeferOption defer_option =
+      !media_query_matches || owner_->IsAlternate() ? FetchParameters::kLazyLoad
+                                                    : FetchParameters::kNoDefer;
 
-  CrossOriginAttributeValue cross_origin =
-      GetCrossOriginAttributeValue(owner_->FastGetAttribute(crossoriginAttr));
-  if (cross_origin != kCrossOriginAttributeNotSet) {
-    params.SetCrossOriginAccessControl(GetDocument().GetSecurityOrigin(),
-                                       cross_origin);
-    SetFetchFollowingCORS();
-  }
-
-  String integrity_attr = owner_->FastGetAttribute(integrityAttr);
-  if (!integrity_attr.IsEmpty()) {
-    IntegrityMetadataSet metadata_set;
-    SubresourceIntegrity::ParseIntegrityAttribute(
-        integrity_attr, SubresourceIntegrityHelper::GetFeatures(&GetDocument()),
-        metadata_set);
-    params.SetIntegrityMetadata(metadata_set);
-    params.MutableResourceRequest().SetFetchIntegrity(integrity_attr);
-  }
-  CSSStyleSheetResource::Fetch(params, GetDocument().Fetcher(), this);
+  owner_->LoadStylesheet(params, charset, defer_option, this);
 
   if (loading_ && !GetResource()) {
     // Fetch() synchronous failure case.

third_party/blink/renderer/core/html/link_style.h

@@ -9,6 +9,7 @@
 #include "third_party/blink/renderer/core/dom/node.h"
 #include "third_party/blink/renderer/core/html/link_resource.h"
 #include "third_party/blink/renderer/core/loader/resource/css_style_sheet_resource.h"
+#include "third_party/blink/renderer/platform/loader/fetch/fetch_parameters.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource_client.h"
 #include "third_party/blink/renderer/platform/wtf/forward.h"
 

third_party/blink/renderer/core/loader/link_loader.cc

@@ -51,13 +51,13 @@
 #include "third_party/blink/renderer/core/loader/modulescript/module_script_fetch_request.h"
 #include "third_party/blink/renderer/core/loader/network_hints_interface.h"
 #include "third_party/blink/renderer/core/loader/private/prerender_handle.h"
+#include "third_party/blink/renderer/core/loader/resource/css_style_sheet_resource.h"
 #include "third_party/blink/renderer/core/loader/resource/link_fetch_resource.h"
 #include "third_party/blink/renderer/core/loader/subresource_integrity_helper.h"
 #include "third_party/blink/renderer/core/script/module_script.h"
 #include "third_party/blink/renderer/core/script/script_loader.h"
 #include "third_party/blink/renderer/core/script/settings_object.h"
 #include "third_party/blink/renderer/platform/loader/fetch/fetch_initiator_type_names.h"
-#include "third_party/blink/renderer/platform/loader/fetch/fetch_parameters.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource_client.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource_fetcher.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource_finish_observer.h"
@@ -693,6 +693,55 @@ bool LinkLoader::LoadLink(
   return true;
 }
 
+void LinkLoader::LoadStylesheet(const LinkLoadParameters& params,
+                                const AtomicString& local_name,
+                                const WTF::TextEncoding& charset,
+                                FetchParameters::DeferOption defer_option,
+                                Document& document,
+                                ResourceClient* link_client) {
+  ResourceRequest resource_request(document.CompleteURL(params.href));
+  ReferrerPolicy referrer_policy = params.referrer_policy;
+  if (referrer_policy != kReferrerPolicyDefault) {
+    resource_request.SetHTTPReferrer(SecurityPolicy::GenerateReferrer(
+        referrer_policy, params.href, document.OutgoingReferrer()));
+  }
+
+  mojom::FetchImportanceMode importance_mode =
+      GetFetchImportanceAttributeValue(params.importance);
+  DCHECK(importance_mode == mojom::FetchImportanceMode::kImportanceAuto ||
+         RuntimeEnabledFeatures::PriorityHintsEnabled());
+  resource_request.SetFetchImportanceMode(importance_mode);
+
+  ResourceLoaderOptions options;
+  options.initiator_info.name = local_name;
+  FetchParameters link_fetch_params(resource_request, options);
+  link_fetch_params.SetCharset(charset);
+
+  link_fetch_params.SetDefer(defer_option);
+
+  link_fetch_params.SetContentSecurityPolicyNonce(params.nonce);
+
+  CrossOriginAttributeValue cross_origin = params.cross_origin;
+  if (cross_origin != kCrossOriginAttributeNotSet) {
+    link_fetch_params.SetCrossOriginAccessControl(document.GetSecurityOrigin(),
+                                                  cross_origin);
+  }
+
+  String integrity_attr = params.integrity;
+  if (!integrity_attr.IsEmpty()) {
+    IntegrityMetadataSet metadata_set;
+    SubresourceIntegrity::ParseIntegrityAttribute(
+        integrity_attr, SubresourceIntegrityHelper::GetFeatures(&document),
+        metadata_set);
+    link_fetch_params.SetIntegrityMetadata(metadata_set);
+    link_fetch_params.MutableResourceRequest().SetFetchIntegrity(
+        integrity_attr);
+  }
+
+  CSSStyleSheetResource::Fetch(link_fetch_params, document.Fetcher(),
+                               link_client);
+}
+
 void LinkLoader::DispatchLinkLoadingErroredAsync() {
   client_->GetLoadingTaskRunner()->PostTask(
       FROM_HERE, WTF::Bind(&LinkLoaderClient::LinkLoadingErrored,

third_party/blink/renderer/core/loader/link_loader.h

@@ -38,6 +38,7 @@
 #include "third_party/blink/renderer/core/loader/link_loader_client.h"
 #include "third_party/blink/renderer/core/script/modulator.h"
 #include "third_party/blink/renderer/platform/cross_origin_attribute_value.h"
+#include "third_party/blink/renderer/platform/loader/fetch/fetch_parameters.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource.h"
 #include "third_party/blink/renderer/platform/prerender_client.h"
 
@@ -114,6 +115,12 @@ class CORE_EXPORT LinkLoader final : public SingleModuleClient,
   bool LoadLink(const LinkLoadParameters&,
                 Document&,
                 const NetworkHintsInterface&);
+  void LoadStylesheet(const LinkLoadParameters&,
+                      const AtomicString&,
+                      const WTF::TextEncoding&,
+                      FetchParameters::DeferOption,
+                      Document&,
+                      ResourceClient*);
   void DispatchLinkLoadingErroredAsync();
 
   enum CanLoadResources {