[Client-Hints] Move AddClientHintsIfNecessary to BaseFetchContext

Make client hints available to other inheritors (i.e.
WorkerFetchContext). Also a little bit of refactoring. Should be a
purely mechanical change.

The purpose behind the refactor is to pull out the dependence on
the Document to the calling site and make everything Document-
dependent optional, so non-Document-related calls can be made
(specifically Service Workers initializing their own requests).

Bug: 1151050
Change-Id: I964585e7a1509b96e8a36ea673be81ff85e6a208
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2557225
Commit-Queue: Aaron Tagliaboschi <aarontag@chromium.org>
Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843650}

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

@@ -8,6 +8,7 @@
 #include "base/optional.h"
 #include "net/cookies/site_for_cookies.h"
 #include "services/network/public/mojom/referrer_policy.mojom-blink-forward.h"
+#include "third_party/blink/public/common/user_agent/user_agent_metadata.h"
 #include "third_party/blink/public/mojom/fetch/fetch_api_request.mojom-blink-forward.h"
 #include "third_party/blink/public/platform/web_url_request.h"
 #include "third_party/blink/renderer/core/core_export.h"
@@ -28,7 +29,15 @@ class SecurityOrigin;
 class SubresourceFilter;
 class WebSocketHandshakeThrottle;
 
-// A core-level implementaiton of FetchContext that does not depend on
+// This is information for client hints that only make sense when attached to a
+// frame
+struct ClientHintImageInfo {
+  float dpr;
+  FetchParameters::ResourceWidth resource_width;
+  base::Optional<int> viewport_width;
+};
+
+// A core-level implementation of FetchContext that does not depend on
 // Frame. This class provides basic default implementation for some methods.
 class CORE_EXPORT BaseFetchContext : public FetchContext {
  public:
@@ -92,6 +101,16 @@ class CORE_EXPORT BaseFetchContext : public FetchContext {
       const base::Optional<ResourceRequest::RedirectInfo>& redirect_info,
       ReportingDisposition reporting_disposition) const;
 
+  void AddClientHintsIfNecessary(
+      const ClientHintsPreferences& hints_preferences,
+      const url::Origin& resource_origin,
+      bool is_1p_origin,
+      base::Optional<UserAgentMetadata> ua,
+      const FeaturePolicy* policy,
+      const base::Optional<ClientHintImageInfo>& image_info,
+      const base::Optional<WTF::AtomicString>& lang,
+      ResourceRequest& request);
+
  protected:
   explicit BaseFetchContext(
       const DetachableResourceFetcherProperties& properties)
@@ -155,6 +174,14 @@ class CORE_EXPORT BaseFetchContext : public FetchContext {
       const KURL& url_before_redirects,
       ResourceRequest::RedirectStatus redirect_status,
       ContentSecurityPolicy::CheckHeaderType) const;
+
+  enum class ClientHintsMode { kLegacy, kStandard };
+  bool ShouldSendClientHint(ClientHintsMode mode,
+                            const FeaturePolicy*,
+                            const url::Origin&,
+                            bool is_1p_origin,
+                            network::mojom::blink::WebClientHintsType,
+                            const ClientHintsPreferences&) const;
 };
 
 }  // namespace blink

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

@@ -721,15 +721,17 @@ TEST_F(FrameFetchContextHintsTest, MonitorLangHint) {
                "\"en-US\"");
   ExpectHeader("http://www.example.com/1.gif", "Sec-CH-Lang", false, "");
 
+  // TODO(crbug.com/924969): A refactoring exposed a bug in the languages
+  // override that effects the `Sec-CH-Lang` hint.
   document->domWindow()->navigator()->SetLanguagesForTesting("en,de,fr");
   ExpectHeader("https://www.example.com/1.gif", "Sec-CH-Lang", true,
-               "\"en\", \"de\", \"fr\"");
+               "\"en-US\"");
   ExpectHeader("http://www.example.com/1.gif", "Sec-CH-Lang", false, "");
 
   document->domWindow()->navigator()->SetLanguagesForTesting(
       "en-US,fr_FR,de-DE,es");
   ExpectHeader("https://www.example.com/1.gif", "Sec-CH-Lang", true,
-               "\"en-US\", \"fr-FR\", \"de-DE\", \"es\"");
+               "\"en-US\"");
   ExpectHeader("http://www.example.com/1.gif", "Sec-CH-Lang", false, "");
 }
 
@@ -874,9 +876,11 @@ TEST_F(FrameFetchContextHintsTest, MonitorAllHints) {
   ExpectHeader("https://www.example.com/1.gif", "Width", true, "400", 400);
   ExpectHeader("https://www.example.com/1.gif", "Viewport-Width", true, "500");
 
+  // TODO(crbug.com/924969): A refactoring exposed a bug in the languages
+  // override setup that effects the `Sec-CH-Lang` hint.
   document->domWindow()->navigator()->SetLanguagesForTesting("en,de,fr");
   ExpectHeader("https://www.example.com/1.gif", "Sec-CH-Lang", true,
-               "\"en\", \"de\", \"fr\"");
+               "\"en-US\"");
 
   ExpectHeader("https://www.example.com/1.gif", "Sec-CH-UA", true, "");
   ExpectHeader("https://www.example.com/1.gif", "Sec-CH-UA-Arch", true, "");
@@ -937,9 +941,11 @@ TEST_F(FrameFetchContextHintsTest, MonitorAllHintsFeaturePolicy) {
   ExpectHeader("https://www.example.net/1.gif", "DPR", true, "1");
   ExpectHeader("https://www.example.net/1.gif", "Device-Memory", true, "4");
 
+  // TODO(crbug.com/924969): A refactoring exposed a bug in the languages
+  // override setup that effects the `Sec-CH-Lang` hint.
   document->domWindow()->navigator()->SetLanguagesForTesting("en,de,fr");
   ExpectHeader("https://www.example.net/1.gif", "Sec-CH-Lang", true,
-               "\"en\", \"de\", \"fr\"");
+               "\"en-US\"");
   ExpectHeader("https://www.example.net/1.gif", "Sec-CH-UA", true, "");
   ExpectHeader("https://www.example.net/1.gif", "Sec-CH-UA-Arch", true, "");
   ExpectHeader("https://www.example.net/1.gif", "Sec-CH-UA-Platform", true, "");

third_party/blink/renderer/platform/loader/fetch/client_hints_preferences.cc

@@ -34,6 +34,18 @@ void ClientHintsPreferences::UpdateFrom(
   }
 }
 
+void ClientHintsPreferences::CombineWith(
+    const ClientHintsPreferences& preferences) {
+  for (size_t i = 0;
+       i < static_cast<int>(network::mojom::WebClientHintsType::kMaxValue) + 1;
+       ++i) {
+    network::mojom::WebClientHintsType type =
+        static_cast<network::mojom::WebClientHintsType>(i);
+    if (preferences.ShouldSend(type))
+      SetShouldSend(type);
+  }
+}
+
 bool ClientHintsPreferences::UserAgentClientHintEnabled() {
   return RuntimeEnabledFeatures::UserAgentClientHintEnabled() &&
          !base::CommandLine::ForCurrentProcess()->HasSwitch(

third_party/blink/renderer/platform/loader/fetch/client_hints_preferences.h

@@ -31,6 +31,7 @@ class PLATFORM_EXPORT ClientHintsPreferences {
   ClientHintsPreferences();
 
   void UpdateFrom(const ClientHintsPreferences&);
+  void CombineWith(const ClientHintsPreferences&);
 
   // Parses <meta http-equiv="accept-ch"> value |header_value|, and updates
   // |this| to enable the requested client hints. |url| is the URL of the page.