Bug 1847811 - Remove network.preload pref. r=necko-reviewers,anti-tracking-reviewers,pbz,kershaw

Having it disabled is not web compatible, and there's no strong reason
to keep it, IMO.

If we want another pref to determine whether preloads are actually
triggered we can add it in the future.

Differential Revision: https://phabricator.services.mozilla.com/D186014

dom/base/test/referrer_helper.js

@@ -79,10 +79,6 @@ function resetState() {
  * testing if referrer header is sent correctly
  */
 var tests = (function* () {
-  yield SpecialPowers.pushPrefEnv(
-    { set: [["network.preload", true]] },
-    advance
-  );
   yield SpecialPowers.pushPrefEnv(
     { set: [["security.mixed_content.block_active_content", false]] },
     advance

dom/base/test/test_bug1222633.html

@@ -71,12 +71,10 @@ const CROSS_ORIGIN = "http://example.com" + SJS_PATH;
 
 SimpleTest.waitForExplicitFinish();
 
-SpecialPowers.pushPrefEnv({"set": [["network.preload", true]]})
-
 // test same origin
-.then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=200&cacheControl=no-cache", false, true))
+testPreloadEvent(SAME_ORIGIN + "?statusCode=200&cacheControl=no-cache", false, true)
-.then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=404&cacheControl=no-cache", false, false))
+  .then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=404&cacheControl=no-cache", false, false))
-.then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=200&cacheControl=max-age%3D120", false, true))
+  .then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=200&cacheControl=max-age%3D120", false, true))
 .then(() => testPreloadEvent(SAME_ORIGIN + "?statusCode=404&cacheControl=max-age%3D120", false, false))
 
 // test cross origin without CORS

dom/base/test/test_bug1222633_link_update.html

@@ -110,10 +110,8 @@ const CROSS_ORIGIN = "http://example.com";
 
 SimpleTest.waitForExplicitFinish();
 
-SpecialPowers.pushPrefEnv({"set": [["network.preload", true]]})
-
 // Test changing as parameter from a wrong to a correct one.
-.then(() => testPreloadEventAsAttributeChange(SAME_ORIGIN + IMAGE_PATH))
+testPreloadEventAsAttributeChange(SAME_ORIGIN + IMAGE_PATH)
 // Test changing type parameter from a wrong to a correct one for given as parameter.
 .then(() => testPreloadEventAttributeChange(SAME_ORIGIN + IMAGE_PATH, "type", "text/vtt", "image/png"))
 // Test changing media parameter from a wrong to a correct one.

dom/base/test/test_bug1667316.html

@@ -72,68 +72,62 @@ const SAME_ORIGIN = "http://mochi.test:8888" + SJS_PATH;
 const CROSS_ORIGIN = "http://example.com" + SJS_PATH;
 
 SimpleTest.waitForExplicitFinish();
+SpecialPowers.spawnChrome([], () => {
+  let window = this.browsingContext.currentWindowGlobal;
+  window.ChannelEventSink = {
+    _classDescription: "WebRequest channel event sink",
+    _classID: Components.ID("115062f8-92f1-11e5-8b7f-08001110f7ec"),
+    _contractID: "@mozilla.org/webrequest/channel-event-sink;1",
 
-SpecialPowers.pushPrefEnv({"set": [["network.preload", true]]})
+    QueryInterface: ChromeUtils.generateQI(["nsIChannelEventSink", "nsIFactory"]),
 
+    init() {
+      Components.manager
+        .QueryInterface(Ci.nsIComponentRegistrar)
+        .registerFactory(
+          this._classID,
+          this._classDescription,
+          this._contractID,
+          this
+        );
+    },
 
-.then(async () => {
+    register() {
-  await SpecialPowers.spawnChrome([], () => {
+      Services.catMan.addCategoryEntry(
-
+        "net-channel-event-sinks",
-let window = this.browsingContext.currentWindowGlobal;
-window.ChannelEventSink = {
-  _classDescription: "WebRequest channel event sink",
-  _classID: Components.ID("115062f8-92f1-11e5-8b7f-08001110f7ec"),
-  _contractID: "@mozilla.org/webrequest/channel-event-sink;1",
-
-  QueryInterface: ChromeUtils.generateQI(["nsIChannelEventSink", "nsIFactory"]),
-
-  init() {
-    Components.manager
-      .QueryInterface(Ci.nsIComponentRegistrar)
-      .registerFactory(
-        this._classID,
-        this._classDescription,
         this._contractID,
-        this
+        this._contractID,
+        false,
+        true
       );
-  },
+    },
 
-  register() {
+    unregister() {
-    Services.catMan.addCategoryEntry(
+      Components.manager
-      "net-channel-event-sinks",
+        .QueryInterface(Ci.nsIComponentRegistrar)
-      this._contractID,
+        .unregisterFactory(this._classID, window.ChannelEventSink);
-      this._contractID,
+      Services.catMan.deleteCategoryEntry(
-      false,
+        "net-channel-event-sinks",
-      true
+        this._contractID,
-    );
+        false
-  },
+      );
+    },
 
-  unregister() {
+    // nsIChannelEventSink implementation
-    Components.manager
+    asyncOnChannelRedirect(oldChannel, newChannel, flags, redirectCallback) {
-      .QueryInterface(Ci.nsIComponentRegistrar)
+      // Abort the redirection.
-      .unregisterFactory(this._classID, window.ChannelEventSink);
+      redirectCallback.onRedirectVerifyCallback(Cr.NS_ERROR_NO_INTERFACE);
-    Services.catMan.deleteCategoryEntry(
+    },
-      "net-channel-event-sinks",
-      this._contractID,
-      false
-    );
-  },
 
-  // nsIChannelEventSink implementation
+    // nsIFactory implementation
-  asyncOnChannelRedirect(oldChannel, newChannel, flags, redirectCallback) {
+    createInstance(iid) {
-    // Abort the redirection.
+      return this.QueryInterface(iid);
-    redirectCallback.onRedirectVerifyCallback(Cr.NS_ERROR_NO_INTERFACE);
+    },
-  },
+  };
 
-  // nsIFactory implementation
+  window.ChannelEventSink.init();
-  createInstance(iid) {
+  window.ChannelEventSink.register();
-    return this.QueryInterface(iid);
+})
-  },
-};
-
-window.ChannelEventSink.init();
-window.ChannelEventSink.register();
-})})
 
 // test cross origin by redirection without CORS
 .then(() => testPreloadEvent(SAME_ORIGIN + "?redirect=crossorigin&statusCode=200&cacheControl=no-cache", false, false))

dom/html/HTMLLinkElement.cpp

@@ -309,26 +309,21 @@ void HTMLLinkElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
 }
 
 // Keep this and the arrays below in sync with ToLinkMask in LinkStyle.cpp.
-#define SUPPORTED_REL_VALUES_BASE                                              \
+#define SUPPORTED_REL_VALUES_BASE                                           \
-  "prefetch", "dns-prefetch", "stylesheet", "next", "alternate", "preconnect", \
+  "preload", "prefetch", "dns-prefetch", "stylesheet", "next", "alternate", \
-      "icon", "search", nullptr
+      "preconnect", "icon", "search", nullptr
 
 static const DOMTokenListSupportedToken sSupportedRelValueCombinations[][12] = {
     {SUPPORTED_REL_VALUES_BASE},
     {"manifest", SUPPORTED_REL_VALUES_BASE},
-    {"preload", SUPPORTED_REL_VALUES_BASE},
-    {"preload", "manifest", SUPPORTED_REL_VALUES_BASE},
     {"modulepreload", SUPPORTED_REL_VALUES_BASE},
-    {"modulepreload", "manifest", SUPPORTED_REL_VALUES_BASE},
+    {"modulepreload", "manifest", SUPPORTED_REL_VALUES_BASE}};
-    {"modulepreload", "preload", SUPPORTED_REL_VALUES_BASE},
-    {"modulepreload", "preload", "manifest", SUPPORTED_REL_VALUES_BASE}};
 #undef SUPPORTED_REL_VALUES_BASE
 
 nsDOMTokenList* HTMLLinkElement::RelList() {
   if (!mRelList) {
     int index = (StaticPrefs::dom_manifest_enabled() ? 1 : 0) |
-                (StaticPrefs::network_preload() ? 2 : 0) |
+                (StaticPrefs::network_modulepreload() ? 2 : 0);
-                (StaticPrefs::network_modulepreload() ? 4 : 0);
 
     mRelList = new nsDOMTokenList(this, nsGkAtoms::rel,
                                   sSupportedRelValueCombinations[index]);

dom/manifest/test/test_link_relList_supports_manifest.html

@@ -15,16 +15,16 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1596040
 
   async function run() {
     const prefSetting = [
-      { manifest: true, preload: true },
+      { manifest: true, modulepreload: true },
-      { manifest: true, preload: false },
+      { manifest: true, modulepreload: false },
-      { manifest: false, preload: true },
+      { manifest: false, modulepreload: true },
-      { manifest: false, preload: false },
+      { manifest: false, modulepreload: false },
     ];
-    for (const { manifest, preload } of prefSetting) {
+    for (const { manifest, modulepreload } of prefSetting) {
       await SpecialPowers.pushPrefEnv({
         set: [
           ["dom.manifest.enabled", manifest],
-          ["network.preload", preload],
+          ["network.modulepreload", modulepreload],
         ],
       });
       const { relList } = document.createElement("link");
@@ -34,9 +34,9 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1596040
         `Expected manifest to be ${manifest}`
       );
       is(
-        relList.supports("preload"),
+        relList.supports("modulepreload"),
-        preload,
+        modulepreload,
-        `Expected preload to be ${preload}`
+        `Expected preload to be ${modulepreload}`
       );
     }
   }

dom/security/test/csp/test_link_rel_preload.html

@@ -68,13 +68,7 @@ function checkFinished() {
 }
 
 SimpleTest.waitForExplicitFinish();
-
+document.getElementById("testframe").src = "file_link_rel_preload.html";
-SpecialPowers.pushPrefEnv(
-  {'set':[["network.preload", true]]},
-  function() {
-    document.getElementById("testframe").src = "file_link_rel_preload.html";
-  });
-
 </script>
 </body>
 </html>

dom/security/test/referrer-policy/referrer_helper.js

@@ -79,10 +79,6 @@ function resetState() {
  * testing if referrer header is sent correctly
  */
 var tests = (function* () {
-  yield SpecialPowers.pushPrefEnv(
-    { set: [["network.preload", true]] },
-    advance
-  );
   yield SpecialPowers.pushPrefEnv(
     { set: [["security.mixed_content.block_active_content", false]] },
     advance

image/imgLoader.cpp

@@ -2330,7 +2330,7 @@ nsresult imgLoader::LoadImage(
   }
 
   // Look in the preloaded images of loading document first.
-  if (StaticPrefs::network_preload() && !aLinkPreload && aLoadingDocument) {
+  if (!aLinkPreload && aLoadingDocument) {
     // All Early Hints preloads are Link preloads, therefore we don't have a
     // Early Hints preload here
     MOZ_ASSERT(!aEarlyHintPreloaderId);

modules/libpref/init/StaticPrefList.yaml

@@ -11691,13 +11691,6 @@
   value: false
   mirror: always
 
-# Enables `<link rel="preload">` tag and `Link: rel=preload` response header
-# handling.
-- name: network.preload
-  type: RelaxedAtomicBool
-  value: true
-  mirror: always
-
 # Enables `<link rel="preconnect">` tag and `Link: rel=preconnect` response header
 # handling.
 - name: network.preconnect

netwerk/protocol/http/EarlyHintPreloader.cpp

@@ -209,8 +209,7 @@ void EarlyHintPreloader::MaybeCreateAndInsertPreload(
   ASDestination destination = static_cast<ASDestination>(as.GetEnumValue());
   CollectResourcesTypeTelemetry(destination);
 
-  if (!StaticPrefs::network_early_hints_enabled() ||
+  if (!StaticPrefs::network_early_hints_enabled()) {
-      !StaticPrefs::network_preload()) {
     return;
   }
 

netwerk/test/browser/browser_103_preload.js

@@ -34,18 +34,6 @@ add_task(async function test_103_preload_disabled() {
   Services.prefs.setBoolPref("network.early-hints.enabled", true);
 });
 
-// Test that with preload config option disabled, no early hint requests are made
-add_task(async function test_103_preload_disabled() {
-  Services.prefs.setBoolPref("network.preload", false);
-  await test_hint_preload(
-    "test_103_preload_disabled",
-    "https://example.com",
-    "https://example.com/browser/netwerk/test/browser/early_hint_pixel.sjs",
-    { hinted: 0, normal: 1 }
-  );
-  Services.prefs.clearUserPref("network.preload");
-});
-
 // Preload with same origin in secure context with mochitest http proxy
 add_task(async function test_103_preload_https() {
   await test_hint_preload(

parser/html/nsHtml5TreeBuilderCppSupplement.h

@@ -302,8 +302,7 @@ nsIContentHandle* nsHtml5TreeBuilder::createElement(
                 mSpeculativeLoadQueue.AppendElement()->InitPreconnect(
                     url, crossOrigin);
               }
-            } else if (mozilla::StaticPrefs::network_preload() &&
+            } else if (rel.LowerCaseEqualsASCII("preload")) {
-                       rel.LowerCaseEqualsASCII("preload")) {
               nsHtml5String url =
                   aAttributes->getValue(nsHtml5AttributeName::ATTR_HREF);
               if (url) {

testing/profiles/web-platform/user.js

@@ -27,8 +27,6 @@ user_pref("focusmanager.testmode", true);
 user_pref("media.navigator.streams.fake", true);
 // Disable permission prompt for getUserMedia
 user_pref("media.navigator.permission.disabled", true);
-// Enable pre-fetching of resources
-user_pref("network.preload", true);
 // Enable direct connection
 user_pref("network.proxy.type", 0);
 // Web-platform-tests load a lot of URLs very quickly. This puts avoidable and

testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py

@@ -663,7 +663,6 @@ class ProfileCreator:
             # TODO: Remove preferences once Firefox 64 is stable (Bug 905404)
             "network.proxy.type": 0,
             "places.history.enabled": False,
-            "network.preload": True,
         })
         if self.e10s:
             profile.set_preferences({"browser.tabs.remote.autostart": True})

testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox_android.py

@@ -125,7 +125,6 @@ class ProfileCreator(FirefoxProfileCreator):
             "dom.disable_open_during_load": False,
             "places.history.enabled": False,
             "dom.send_after_paint_to_content": True,
-            "network.preload": True,
             "browser.tabs.remote.autostart": True,
         })
 

toolkit/components/antitracking/test/xpcshell/test_staticPartition_preload.js

@@ -57,7 +57,6 @@ async function checkCache(originAttributes) {
 add_task(async () => {
   do_get_profile();
 
-  Services.prefs.setBoolPref("network.preload", true);
   Services.prefs.setIntPref("network.cookie.cookieBehavior", 0);
 
   const server = CookieXPCShellUtils.createServer({

uriloader/preload/PreloadService.cpp

@@ -68,10 +68,6 @@ already_AddRefed<PreloaderBase> PreloadService::PreloadLinkElement(
     return nullptr;
   }
 
-  if (!StaticPrefs::network_preload()) {
-    return nullptr;
-  }
-
   nsAutoString as, charset, crossOrigin, integrity, referrerPolicy, rel, srcset,
       sizes, type, url;
 
@@ -123,10 +119,6 @@ void PreloadService::PreloadLinkHeader(
     return;
   }
 
-  if (!StaticPrefs::network_preload()) {
-    return;
-  }
-
   PreloadOrCoalesce(aURI, aURL, aPolicyType, aAs, aType, u""_ns, aSrcset,
                     aSizes, aNonce, aIntegrity, aCORS, aReferrerPolicy,
                     /* aFromHeader = */ true, aEarlyHintPreloaderId);