import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1175138 P1 Make the dom.caches.testing.enabled pref available in workers. r=ehsan (fe47d0e0a)
- Bug 1175138 P2 Expose dom.serviceWorkers.testing.enabled to workers. r=ehsan (efab5d0d3)
- Bug 1160458 - Part 1: Use the CSP of the principal passed to CreateServiceWorker. r=nsm (4d0a1d742)
- Bug 1172948 - Part 3: Add an explicit test case to ensure that authenticated origins that have a non-authenticated parent cannot register a service worker; r=nsm (78b3087c9)
- Bug 803537 - XHR crashes in workers and in debug-builds when blob URLs are used from file scheme documents, r=khuey (aa86f77b7)
- Bug 1163900 - crash in mozilla::net::nsHttpChannelCacheKey::GetData(unsigned int*, nsACString_internal&), r=jduell (adb5ddb01)
- Bug 1147746 - Null check mInterceptListener in HttpChannelChild::ResetInterception; r=jdm (4c8c4e630)
- Bug 1157283 - Recreate IPC redirected HTTP channels as necessary after intercepting the request in the child. r=mayhemer (3b144e45e)
- Bug 1172884 P1 Properly decode body when intercepted response redirects. r=jduell (f49c37d4f)
- Bug 1172884 P2 Add test for synthesizing a redirect to a compressed resource. r=ehsan (823d2122a)
- Bug 1160458 - Part 2: Test. r=nsm (02b9fb3a0)
- Bug 1169249 - Unregister service worker registration when uninstalling a service-worker-enabled application. Tests. r=baku (5509a19d6)
- Bug 1177621 - SharedWorkers should not be shared between a private and a non-private documents, r=nsm (0836234c7)
- Bug 1175138 P3 Expose the devtools SW testing flag on workers. r=ehsan (aade20454)
- Bug 1173467 P3 Pass private browsing flag into CacheStorage factory methods. r=ehsan (c4d062a80)
- Bug 1173467 P4 Add a test to validate Cache in private browsing window. r=ehsan (dde897e69)
- Bug 1162487 - Enable the dom.caches.enabled pref in test_chrome_constructor.html; r=baku (2c73e2929)
- Bug 1175138 P4 Enable dom.caches.testing.enabled in existing tests. r=ehsan (c453e03fb)
- Bug 1175138 P5 Make CacheStorage reject on untrusted origins. r=ehsan (c85424d4e)
- Bug 1175138 P6 Add a simple test to verify CacheStorage rejects in http origin. r=ehsan (5832eb99d)
- Bug 1179567 - Make ServiceWorker keep its document and window alive; r=baku (1ae847884)
- Bug 1179982 - Fix all compile errors in dom/workers on non-unified build. r=mrbkap (d30bece64)

docshell/base/nsDocShell.cpp

@@ -14250,6 +14250,11 @@ nsDocShell::ShouldPrepareForIntercept(nsIURI* aURI, bool aIsNavigate,
     return NS_OK;
   }
 
+  // No in private browsing
+  if (mInPrivateBrowsing) {
+    return NS_OK;
+  }
+
   if (mSandboxFlags) {
     // If we're sandboxed, don't intercept.
     return NS_OK;