Prerender: Replace WebPrerenderRelType with mojom::PrerenderRelType

For code simplification, this CL replaces WebPrerenderRelType with
mojom::PrerenderRelType.

Before this change, WebPrerenderRelType was represented as bit-field.
This is because it was allowed to specify both "prerender"[1] and
"next"[2] types at the same time in the link rel attribute like
<link rel="prefetch next">. However, in that case, "prerender" is just
prioritized[3], so it was unnecessary to keep both the types in the
bit-field.

Therefore this CL introduces the mojom::PrerenderRelType as enum instead
of bit-field. This would make code simpler and more readable.

[1] https://html.spec.whatwg.org/C/#link-type-prerender
[2] https://html.spec.whatwg.org/C/#link-type-next
[3] https://source.chromium.org/chromium/chromium/src/+/master:components/prerender/browser/prerender_manager.cc;l=177;drc=ee49bcdf8e3a7764fa22b8e9d1ec1d0c9332870f

Bug: n/a
Change-Id: Ida2957a659c7578930bdeac136c72ebc8cacb8b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409890Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807396}

chrome/browser/prerender/prerender_unittest.cc

@@ -53,7 +53,6 @@
 #include "net/http/http_cache.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "third_party/blink/public/common/prerender/prerender_rel_type.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
@@ -149,8 +148,6 @@ int DummyPrerenderContents::g_next_route_id_ = 0;
 
 const gfx::Size kDefaultViewSize(640, 480);
 
-const uint32_t kDefaultRelTypes = blink::kPrerenderRelTypePrerender;
-
 }  // namespace
 
 class UnitTestPrerenderManager : public PrerenderManager {
@@ -401,10 +398,9 @@ class PrerenderTest : public testing::Test {
                     const GURL& initiator_url,
                     int render_process_id,
                     int render_view_id) {
-    blink::mojom::PrerenderAttributesPtr attributes =
-        blink::mojom::PrerenderAttributes::New();
+    auto attributes = blink::mojom::PrerenderAttributes::New();
     attributes->url = url;
-    attributes->rel_types = kDefaultRelTypes;
+    attributes->rel_type = blink::mojom::PrerenderRelType::kPrerender;
     attributes->referrer = blink::mojom::Referrer::New(
         initiator_url, network::mojom::ReferrerPolicy::kDefault);
     attributes->initiator_origin = url::Origin::Create(initiator_url);

components/prerender/browser/prerender_link_manager.cc

@@ -23,7 +23,6 @@
 #include "content/public/common/referrer.h"
 #include "mojo/public/cpp/bindings/associated_remote.h"
 #include "third_party/blink/public/common/associated_interfaces/associated_interface_provider.h"
-#include "third_party/blink/public/common/prerender/prerender_rel_type.h"
 #include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 #include "url/origin.h"
@@ -86,7 +85,7 @@ class PrerenderLinkManager::LinkPrerender {
   int launcher_render_process_id;
   int launcher_render_view_id;
   GURL url;
-  uint32_t rel_types;
+  blink::mojom::PrerenderRelType rel_type;
   content::Referrer referrer;
   url::Origin initiator_origin;
   gfx::Size size;
@@ -124,7 +123,7 @@ PrerenderLinkManager::LinkPrerender::LinkPrerender(
     : launcher_render_process_id(launcher_render_process_id),
       launcher_render_view_id(launcher_render_view_id),
       url(attributes->url),
-      rel_types(attributes->rel_types),
+      rel_type(attributes->rel_type),
       referrer(content::Referrer(*attributes->referrer)),
       initiator_origin(attributes->initiator_origin),
       size(attributes->view_size),
@@ -336,7 +335,7 @@ void PrerenderLinkManager::StartPrerenders() {
         manager_->AddPrerenderFromLinkRelPrerender(
             pending_prerender->launcher_render_process_id,
             pending_prerender->launcher_render_view_id, pending_prerender->url,
-            pending_prerender->rel_types, pending_prerender->referrer,
+            pending_prerender->rel_type, pending_prerender->referrer,
             pending_prerender->initiator_origin, pending_prerender->size);
     if (!handle) {
       // This prerender couldn't be launched, it's gone.

components/prerender/browser/prerender_manager.cc

@@ -52,7 +52,6 @@
 #include "content/public/common/url_constants.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_request_headers.h"
-#include "third_party/blink/public/common/prerender/prerender_rel_type.h"
 #include "ui/gfx/geometry/rect.h"
 
 using content::BrowserThread;
@@ -170,13 +169,20 @@ PrerenderManager::AddPrerenderFromLinkRelPrerender(
     int process_id,
     int route_id,
     const GURL& url,
-    const uint32_t rel_types,
+    blink::mojom::PrerenderRelType rel_type,
     const content::Referrer& referrer,
     const url::Origin& initiator_origin,
     const gfx::Size& size) {
-  Origin origin = rel_types & blink::kPrerenderRelTypePrerender
-                      ? ORIGIN_LINK_REL_PRERENDER_CROSSDOMAIN
-                      : ORIGIN_LINK_REL_NEXT;
+  Origin origin = ORIGIN_LINK_REL_PRERENDER_CROSSDOMAIN;
+  switch (rel_type) {
+    case blink::mojom::PrerenderRelType::kPrerender:
+      origin = ORIGIN_LINK_REL_PRERENDER_CROSSDOMAIN;
+      break;
+    case blink::mojom::PrerenderRelType::kNext:
+      origin = ORIGIN_LINK_REL_NEXT;
+      break;
+  }
+
   SessionStorageNamespace* session_storage_namespace = nullptr;
   // Unit tests pass in a process_id == -1.
   if (process_id != -1) {

components/prerender/browser/prerender_manager.h

@@ -26,6 +26,7 @@
 #include "components/prerender/common/prerender_final_status.h"
 #include "components/prerender/common/prerender_origin.h"
 #include "content/public/browser/render_process_host_observer.h"
+#include "third_party/blink/public/mojom/prerender/prerender.mojom.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
@@ -110,7 +111,7 @@ class PrerenderManager : public content::RenderProcessHostObserver,
       int process_id,
       int route_id,
       const GURL& url,
-      uint32_t rel_types,
+      blink::mojom::PrerenderRelType rel_type,
       const content::Referrer& referrer,
       const url::Origin& initiator_origin,
       const gfx::Size& size);

third_party/blink/public/common/BUILD.gn

@@ -162,7 +162,6 @@ source_set("headers") {
     "peerconnection/peer_connection_tracker_mojom_traits.h",
     "peerconnection/webrtc_ip_handling_policy.h",
     "permissions/permission_utils.h",
-    "prerender/prerender_rel_type.h",
     "scheduler/web_scheduler_tracked_feature.h",
     "security/security_style.h",
     "security_context/insecure_request_policy.h",

third_party/blink/public/common/prerender/prerender_rel_type.h

-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BLINK_PUBLIC_COMMON_PRERENDER_PRERENDER_REL_TYPE_H_
-#define THIRD_PARTY_BLINK_PUBLIC_COMMON_PRERENDER_PRERENDER_REL_TYPE_H_
-
-namespace blink {
-
-// WebPrerenderRelType is a bitfield since multiple rel attributes can be set on
-// the same prerender.
-enum WebPrerenderRelType {
-  kPrerenderRelTypePrerender = 0x1,
-  kPrerenderRelTypeNext = 0x2,
-};
-
-}  // namespace blink
-
-#endif  // THIRD_PARTY_BLINK_PUBLIC_COMMON_PRERENDER_PRERENDER_REL_TYPE_H_

third_party/blink/public/mojom/prerender/prerender.mojom

@@ -40,9 +40,17 @@ interface PrerenderHandle {
   Abandon();
 };
 
+enum PrerenderRelType {
+  // https://html.spec.whatwg.org/C/#link-type-prerender
+  kPrerender,
+
+  // https://html.spec.whatwg.org/C/#link-type-next
+  kNext,
+};
+
 struct PrerenderAttributes {
   url.mojom.Url url;
-  uint32 rel_types;
+  PrerenderRelType rel_type;
   blink.mojom.Referrer referrer;
   url.mojom.Origin initiator_origin;
   gfx.mojom.Size view_size;

third_party/blink/renderer/core/exported/prerendering_test.cc

@@ -36,7 +36,6 @@
 #include "mojo/public/cpp/bindings/receiver_set.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/common/browser_interface_broker_proxy.h"
-#include "third_party/blink/public/common/prerender/prerender_rel_type.h"
 #include "third_party/blink/public/mojom/prerender/prerender.mojom-blink.h"
 #include "third_party/blink/public/platform/web_cache.h"
 #include "third_party/blink/public/platform/web_string.h"
@@ -79,7 +78,9 @@ class MockPrerender : public mojom::blink::PrerenderHandle {
   ~MockPrerender() override = default;
 
   const KURL& Url() const { return attributes_->url; }
-  uint32_t RelTypes() const { return attributes_->rel_types; }
+  mojom::blink::PrerenderRelType RelType() const {
+    return attributes_->rel_type;
+  }
 
   // Returns the number of times |Cancel| was called.
   size_t CancelCount() const { return cancel_count_; }
@@ -260,8 +261,7 @@ TEST_F(PrerenderingTest, SinglePrerender) {
       PrerenderProcessor()->ReleasePrerender();
   EXPECT_TRUE(prerender);
   EXPECT_EQ(KURL("http://prerender.com/"), prerender->Url());
-  EXPECT_EQ(static_cast<unsigned>(kPrerenderRelTypePrerender),
-            prerender->RelTypes());
+  EXPECT_EQ(mojom::blink::PrerenderRelType::kPrerender, prerender->RelType());
 
   EXPECT_EQ(1u, PrerenderProcessor()->AddCount());
   EXPECT_EQ(0u, prerender->CancelCount());

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

@@ -31,7 +31,6 @@
 
 #include "third_party/blink/renderer/core/loader/link_loader.h"
 
-#include "third_party/blink/public/common/prerender/prerender_rel_type.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
@@ -57,20 +56,23 @@ class WebPrescientNetworking;
 
 namespace {
 
-unsigned PrerenderRelTypesFromRelAttribute(
+// Decide the prerender type based on the link rel attribute. Returns
+// base::nullopt if the attribute doesn't indicate the prerender type.
+base::Optional<mojom::blink::PrerenderRelType> PrerenderRelTypeFromRelAttribute(
     const LinkRelAttribute& rel_attribute,
     Document& document) {
-  unsigned result = 0;
+  base::Optional<mojom::blink::PrerenderRelType> rel_type;
   if (rel_attribute.IsLinkPrerender()) {
-    result |= kPrerenderRelTypePrerender;
     UseCounter::Count(document, WebFeature::kLinkRelPrerender);
+    rel_type = mojom::blink::PrerenderRelType::kPrerender;
   }
   if (rel_attribute.IsLinkNext()) {
-    result |= kPrerenderRelTypeNext;
     UseCounter::Count(document, WebFeature::kLinkRelNext);
+    // Prioritize mojom::blink::PrerenderRelType::kPrerender.
+    if (!rel_type)
+      rel_type = mojom::blink::PrerenderRelType::kNext;
   }
-
-  return result;
+  return rel_type;
 }
 
 }  // namespace
@@ -194,15 +196,16 @@ bool LinkLoader::LoadLink(const LinkLoadParameters& params,
   PreloadHelper::ModulePreloadIfNeeded(
       params, document, nullptr /* viewport_description */, this);
 
-  if (const unsigned prerender_rel_types =
-          PrerenderRelTypesFromRelAttribute(params.rel, document)) {
+  base::Optional<mojom::blink::PrerenderRelType> prerender_rel_type =
+      PrerenderRelTypeFromRelAttribute(params.rel, document);
+  if (prerender_rel_type) {
     if (!prerender_) {
       prerender_ = PrerenderHandle::Create(document, this, params.href,
-                                           prerender_rel_types);
+                                           *prerender_rel_type);
     } else if (prerender_->Url() != params.href) {
       prerender_->Cancel();
       prerender_ = PrerenderHandle::Create(document, this, params.href,
-                                           prerender_rel_types);
+                                           *prerender_rel_type);
     }
     // TODO(gavinp): Handle changes to rel types of existing prerenders.
   } else if (prerender_) {

third_party/blink/renderer/core/loader/private/prerender_handle.cc

@@ -42,10 +42,11 @@
 namespace blink {
 
 // static
-PrerenderHandle* PrerenderHandle::Create(Document& document,
-                                         PrerenderClient* client,
-                                         const KURL& url,
-                                         const unsigned prerender_rel_types) {
+PrerenderHandle* PrerenderHandle::Create(
+    Document& document,
+    PrerenderClient* client,
+    const KURL& url,
+    mojom::blink::PrerenderRelType prerender_rel_type) {
   // Prerenders are unlike requests in most ways (for instance, they pass down
   // fragments, and they don't return data), but they do have referrers.
 
@@ -56,10 +57,9 @@ PrerenderHandle* PrerenderHandle::Create(Document& document,
   Referrer referrer = SecurityPolicy::GenerateReferrer(
       context->GetReferrerPolicy(), url, context->OutgoingReferrer());
 
-  mojom::blink::PrerenderAttributesPtr attributes =
-      mojom::blink::PrerenderAttributes::New();
+  auto attributes = mojom::blink::PrerenderAttributes::New();
   attributes->url = url;
-  attributes->rel_types = prerender_rel_types;
+  attributes->rel_type = prerender_rel_type;
   attributes->referrer = mojom::blink::Referrer::New(
       KURL(NullURL(), referrer.referrer), referrer.referrer_policy);
   attributes->initiator_origin = context->GetSecurityOrigin();

third_party/blink/renderer/core/loader/private/prerender_handle.h

@@ -53,10 +53,11 @@ class PrerenderHandle final : public GarbageCollected<PrerenderHandle>,
   USING_PRE_FINALIZER(PrerenderHandle, Dispose);
 
  public:
-  static PrerenderHandle* Create(Document&,
-                                 PrerenderClient*,
-                                 const KURL&,
-                                 unsigned prerender_rel_types);
+  static PrerenderHandle* Create(
+      Document&,
+      PrerenderClient*,
+      const KURL&,
+      mojom::blink::PrerenderRelType prerender_rel_type);
 
   using PassKey = util::PassKey<PrerenderHandle>;
   PrerenderHandle(PassKey,