Revert "Bug 1975753 - Force site specific zoom when RFPTarget::SiteSpecificZoom is active. r=timhuang,tabbrowser-reviewers,dao" for causing bc failures @ browser_ext_tabs_zoom.js

This reverts commit 213240f.

Author: Sandor Molnar

browser/components/resistfingerprinting/test/browser/browser.toml

@@ -58,7 +58,7 @@ support-files = [
 
 ["browser_block_mozAddonManager.js"]
 
-["browser_bug1975753_site_specific_zoom_level.js"]
+["browser_bug1369357_site_specific_zoom_level.js"]
 https_first_disabled = true
 
 ["browser_canvas_iframes.js"]

browser/components/resistfingerprinting/test/browser/browser_bug1369357_site_specific_zoom_level.js

@@ -0,0 +1,77 @@
+"use strict";
+
+const PATH_NET = TEST_PATH + "file_dummy.html";
+const PATH_ORG = PATH_NET.replace("example.net", "example.org");
+
+add_task(async function () {
+  let tab1, tab1Zoom, tab2, tab2Zoom, tab3, tab3Zoom;
+
+  tab1 = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_NET);
+  await FullZoom.enlarge();
+  tab1Zoom = ZoomManager.getZoomForBrowser(tab1.linkedBrowser);
+
+  tab2 = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_NET);
+  tab2Zoom = ZoomManager.getZoomForBrowser(tab2.linkedBrowser);
+
+  is(
+    tab2Zoom,
+    tab1Zoom,
+    "privacy.resistFingerprinting is false, site-specific zoom level should be enabled"
+  );
+
+  await SpecialPowers.pushPrefEnv({
+    set: [["privacy.resistFingerprinting", true]],
+  });
+
+  tab3 = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_NET);
+  tab3Zoom = ZoomManager.getZoomForBrowser(tab3.linkedBrowser);
+
+  isnot(
+    tab3Zoom,
+    tab1Zoom,
+    "privacy.resistFingerprinting is true, site-specific zoom level should be disabled"
+  );
+
+  await FullZoom.reset();
+
+  BrowserTestUtils.removeTab(tab1);
+  BrowserTestUtils.removeTab(tab2);
+  BrowserTestUtils.removeTab(tab3);
+
+  await SpecialPowers.popPrefEnv();
+});
+
+add_task(async function exempt_domain() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_NET);
+  await FullZoom.enlarge();
+  const netZoomOriginal = ZoomManager.getZoomForBrowser(tab.linkedBrowser);
+  is(netZoomOriginal, 1.1, "Initial zoom is 110%");
+  await BrowserTestUtils.removeTab(tab);
+
+  tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_ORG);
+  await FullZoom.enlarge();
+  const orgZoomOriginal = ZoomManager.getZoomForBrowser(tab.linkedBrowser);
+  is(orgZoomOriginal, 1.1, "Initial zoom is 110%");
+  await BrowserTestUtils.removeTab(tab);
+
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["privacy.resistFingerprinting.exemptedDomains", "example.net"],
+      ["privacy.resistFingerprinting", true],
+    ],
+  });
+
+  tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_NET);
+  const netZoom = ZoomManager.getZoomForBrowser(tab.linkedBrowser);
+  is(netZoom, 1.1, "exempted example.net tab should have kept zoom level");
+  await FullZoom.reset();
+  await BrowserTestUtils.removeTab(tab);
+
+  tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, PATH_ORG);
+  const orgZoom = ZoomManager.getZoomForBrowser(tab.linkedBrowser);
+  is(orgZoom, 1.0, "example.org tab has its zoom reset to default 100%");
+  await FullZoom.reset();
+  await BrowserTestUtils.removeTab(tab);
+
+  await SpecialPowers.popPrefEnv();
+});

browser/components/resistfingerprinting/test/browser/browser_bug1975753_site_specific_zoom_level.js

@@ -27,7 +27,7 @@ var FullZoom = {
   // events before we're initialized.
   _initialLocations: new WeakMap(),
 
-  get siteSpecificPref() {
+  get siteSpecific() {
     if (this._siteSpecificPref === undefined) {
       this._siteSpecificPref = Services.prefs.getBoolPref(
         "browser.zoom.siteSpecific"
@@ -236,7 +236,7 @@ var FullZoom = {
     // to the new location.
     this._ignorePendingZoomAccesses(browser);
 
-    if (!aURI || (aIsTabSwitch && !this.siteSpecificPref)) {
+    if (!aURI || (aIsTabSwitch && !this._isSiteSpecific(browser))) {
       this._notifyOnLocationChange(browser);
       return;
     }
@@ -530,13 +530,13 @@ var FullZoom = {
     if (
       !aBrowser.mInitialized ||
       aBrowser.isSyntheticDocument ||
-      (!this.siteSpecificPref && aBrowser.tabHasCustomZoom)
+      (!this._isSiteSpecific(aBrowser) && aBrowser.tabHasCustomZoom)
     ) {
       this._executeSoon(aCallback);
       return;
     }
 
-    if (aValue !== undefined && this.siteSpecificPref) {
+    if (aValue !== undefined && this._isSiteSpecific(aBrowser)) {
       ZoomManager.setZoomForBrowser(aBrowser, this._ensureValid(aValue));
       this._ignorePendingZoomAccesses(aBrowser);
       this._executeSoon(aCallback);
@@ -563,11 +563,11 @@ var FullZoom = {
    * @param browser  The zoom of this browser will be saved.  Required.
    */
   _applyZoomToPref: function FullZoom__applyZoomToPref(browser) {
-    if (!this.siteSpecificPref || browser.isSyntheticDocument) {
+    if (!this._isSiteSpecific(browser) || browser.isSyntheticDocument) {
       // If site-specific zoom is disabled, we have called this function
       // to adjust our tab's zoom level. It is now considered "custom"
       // and we mark that here.
-      browser.tabHasCustomZoom = !this.siteSpecificPref;
+      browser.tabHasCustomZoom = !this._isSiteSpecific(browser);
       return null;
     }
 
@@ -697,6 +697,23 @@ var FullZoom = {
     return aValue;
   },
 
+  // Whether to remember the site specific zoom level for this browser.
+  // This returns false when `browser.zoom.siteSpecific` is false or
+  // the browser has content loaded that should resist fingerprinting.
+  _isSiteSpecific(aBrowser) {
+    if (!this.siteSpecific) {
+      return false;
+    }
+    return (
+      !aBrowser?.browsingContext?.topWindowContext.shouldResistFingerprinting ||
+      !ChromeUtils.shouldResistFingerprinting(
+        "SiteSpecificZoom",
+        aBrowser?.browsingContext?.topWindowContext
+          .overriddenFingerprintingSettings
+      )
+    );
+  },
+
   /**
    * Gets the load context from the given Browser.
    *

browser/components/tabbrowser/content/browser-fullZoom.js

@@ -416,114 +416,32 @@ const CookieBannerExecutedRecordCleaner = {
 
 // A cleaner for cleaning fingerprinting protection states.
 const FingerprintingProtectionStateCleaner = {
-  async _maybeClearSiteSpecificZoom(
-    deleteAll,
-    aSchemelessSite,
-    aOriginAttributes = {}
-  ) {
-    if (
-      !ChromeUtils.shouldResistFingerprinting("SiteSpecificZoom", null, true)
-    ) {
-      return;
-    }
-
-    const cps2 = Cc["@mozilla.org/content-pref/service;1"].getService(
-      Ci.nsIContentPrefService2
-    );
-    const ZOOM_PREF_NAME = "browser.content.full-zoom";
-
-    await new Promise((aResolve, aReject) => {
-      if (deleteAll) {
-        cps2.removeByName(ZOOM_PREF_NAME, null, {
-          handleCompletion: aReason => {
-            if (aReason === cps2.COMPLETE_ERROR) {
-              aReject();
-            } else {
-              aResolve();
-            }
-          },
-        });
-      } else {
-        aOriginAttributes =
-          ChromeUtils.fillNonDefaultOriginAttributes(aOriginAttributes);
-
-        let loadContext;
-        if (
-          aOriginAttributes.privateBrowsingId ==
-          Services.scriptSecurityManager.DEFAULT_PRIVATE_BROWSING_ID
-        ) {
-          loadContext = Cu.createLoadContext();
-        } else {
-          loadContext = Cu.createPrivateLoadContext();
-        }
-
-        cps2.removeBySubdomainAndName(
-          aSchemelessSite,
-          ZOOM_PREF_NAME,
-          loadContext,
-          {
-            handleCompletion: aReason => {
-              if (aReason === cps2.COMPLETE_ERROR) {
-                aReject();
-              } else {
-                aResolve();
-              }
-            },
-          }
-        );
-      }
-    });
-  },
-
   async deleteAll() {
     Services.rfp.cleanAllRandomKeys();
-
-    await this._maybeClearSiteSpecificZoom(true);
   },
 
   async deleteByPrincipal(aPrincipal) {
     Services.rfp.cleanRandomKeyByPrincipal(aPrincipal);
-
-    await this._maybeClearSiteSpecificZoom(
-      false,
-      aPrincipal.host,
-      aPrincipal.originAttributes
-    );
   },
 
   async deleteBySite(aSchemelessSite, aOriginAttributesPattern) {
     Services.rfp.cleanRandomKeyBySite(
       aSchemelessSite,
       aOriginAttributesPattern
     );
-
-    await this._maybeClearSiteSpecificZoom(
-      false,
-      aSchemelessSite,
-      aOriginAttributesPattern
-    );
   },
 
   async deleteByHost(aHost, aOriginAttributesPattern) {
     Services.rfp.cleanRandomKeyByHost(
       aHost,
       JSON.stringify(aOriginAttributesPattern)
     );
-
-    await this._maybeClearSiteSpecificZoom(
-      false,
-      aHost,
-      aOriginAttributesPattern
-    );
   },
 
   async deleteByOriginAttributes(aOriginAttributesString) {
     Services.rfp.cleanRandomKeyByOriginAttributesPattern(
       aOriginAttributesString
     );
-
-    // For deleteByOriginAttributes, we only receive userContextId which is not enough to target specific
-    // site-specific zooms. So we don't clear site-specific zooms here.
   },
 };