--- a/js/xpconnect/src/XPCComponents.cpp
+++ b/js/xpconnect/src/XPCComponents.cpp
@@ -158,19 +158,17 @@ nsXPCComponents_Interfaces::GetClassID(n
 {
     *aClassID = nullptr;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_Interfaces::GetFlags(uint32_t* aFlags)
 {
-    // Mark ourselves as a DOM object so that instances may be created in
-    // unprivileged scopes.
-    *aFlags = nsIClassInfo::DOM_OBJECT;
+    *aFlags = 0;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_Interfaces::GetClassIDNoAlloc(nsCID* aClassIDNoAlloc)
 {
     return NS_ERROR_NOT_AVAILABLE;
 }
@@ -358,19 +356,17 @@ nsXPCComponents_InterfacesByID::GetClass
 {
     *aClassID = nullptr;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_InterfacesByID::GetFlags(uint32_t* aFlags)
 {
-    // Mark ourselves as a DOM object so that instances may be created in
-    // unprivileged scopes.
-    *aFlags = nsIClassInfo::DOM_OBJECT;
+    *aFlags = 0;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_InterfacesByID::GetClassIDNoAlloc(nsCID* aClassIDNoAlloc)
 {
     return NS_ERROR_NOT_AVAILABLE;
 }
@@ -952,19 +948,17 @@ nsXPCComponents_Results::GetClassID(nsCI
 {
     *aClassID = nullptr;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_Results::GetFlags(uint32_t* aFlags)
 {
-    // Mark ourselves as a DOM object so that instances may be created in
-    // unprivileged scopes.
-    *aFlags = nsIClassInfo::DOM_OBJECT;
+    *aFlags = 0;
     return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_Results::GetClassIDNoAlloc(nsCID* aClassIDNoAlloc)
 {
     return NS_ERROR_NOT_AVAILABLE;
 }
@@ -3260,20 +3254,20 @@ NS_IMPL_QUERY_INTERFACE(ComponentsSH, ns
 #define NSXPCCOMPONENTSBASE_CID \
 { 0xc62998e5, 0x95f1, 0x4058, \
   { 0xa5, 0x09, 0xec, 0x21, 0x66, 0x18, 0x92, 0xb9 } }
 
 #define NSXPCCOMPONENTS_CID \
 { 0x3649f405, 0xf0ec, 0x4c28, \
     { 0xae, 0xb0, 0xaf, 0x9a, 0x51, 0xe4, 0x4c, 0x81 } }
 
-NS_IMPL_CLASSINFO(nsXPCComponentsBase, &ComponentsSH::Get, nsIClassInfo::DOM_OBJECT, NSXPCCOMPONENTSBASE_CID)
+NS_IMPL_CLASSINFO(nsXPCComponentsBase, &ComponentsSH::Get, 0, NSXPCCOMPONENTSBASE_CID)
 NS_IMPL_ISUPPORTS_CI(nsXPCComponentsBase, nsIXPCComponentsBase)
 
-NS_IMPL_CLASSINFO(nsXPCComponents, &ComponentsSH::Get, nsIClassInfo::DOM_OBJECT, NSXPCCOMPONENTS_CID)
+NS_IMPL_CLASSINFO(nsXPCComponents, &ComponentsSH::Get, 0, NSXPCCOMPONENTS_CID)
 // Below is more or less what NS_IMPL_ISUPPORTS_CI_INHERITED1 would look like
 // if it existed.
 NS_IMPL_ADDREF_INHERITED(nsXPCComponents, nsXPCComponentsBase)
 NS_IMPL_RELEASE_INHERITED(nsXPCComponents, nsXPCComponentsBase)
 NS_INTERFACE_MAP_BEGIN(nsXPCComponents)
     NS_INTERFACE_MAP_ENTRY(nsIXPCComponents)
     NS_IMPL_QUERY_CLASSINFO(nsXPCComponents)
 NS_INTERFACE_MAP_END_INHERITING(nsXPCComponentsBase)

--- a/js/xpconnect/tests/unit/test_allowedDomains.js
+++ b/js/xpconnect/tests/unit/test_allowedDomains.js
@@ -33,14 +33,9 @@ function run_test() {
     } catch (e) {    
       Assert.ok(e.message && e.message.includes("Permission denied to access property"));
     }  
   }
   
   evalAndCatch("objC.prop1", sbMaster);
   evalAndCatch("objMaster.prop1", sbA);
   evalAndCatch("objMaster.prop1", sbSubset);
-  
-  // Bug 777705:
-  sbMaster.Components = Cu.getComponentsForScope(sbMaster);
-  Cu.evalInSandbox("Components.interfaces", sbMaster);
-  Assert.ok(true);
 }

--- a/js/xpconnect/tests/unit/test_components.js
+++ b/js/xpconnect/tests/unit/test_components.js
@@ -1,52 +1,24 @@
 function run_test() {
   var sb1 = Cu.Sandbox("http://www.blah.com");
-  var sb2 = Cu.Sandbox("http://www.blah.com");
-  var sb3 = Cu.Sandbox(this);
-  var sb4 = Cu.Sandbox("http://www.other.com");
+  var sb2 = Cu.Sandbox(this);
   var rv;
 
-  // Components is normally hidden from content on the XBL scope chain, but we
-  // expose it to content here to make sure that the security wrappers work
-  // regardless.
-  [sb1, sb2, sb4].forEach(function(x) { x.Components = Cu.getComponentsForScope(x); });
-
   // non-chrome accessing chrome Components
   sb1.C = Components;
+  checkThrows("C.interfaces", sb1);
   checkThrows("C.utils", sb1);
   checkThrows("C.classes", sb1);
 
-  // non-chrome accessing own Components
-  Assert.equal(Cu.evalInSandbox("typeof Components.interfaces", sb1), 'object');
-  Assert.equal(Cu.evalInSandbox("typeof Components.utils", sb1), 'undefined');
-  Assert.equal(Cu.evalInSandbox("typeof Components.classes", sb1), 'undefined');
-
-  // Make sure an unprivileged Components is benign.
-  var C2 = Cu.evalInSandbox("Components", sb2);
-  var whitelist = ['interfaces', 'interfacesByID', 'results', 'isSuccessCode', 'QueryInterface'];
-  for (var prop in Components) {
-    info("Checking " + prop);
-    Assert.equal((prop in C2), whitelist.includes(prop));
-  }
-
-  // non-chrome same origin
-  sb1.C2 = C2;
-  Assert.equal(Cu.evalInSandbox("typeof C2.interfaces", sb1), 'object');
-  Assert.equal(Cu.evalInSandbox("typeof C2.utils", sb1), 'undefined');
-  Assert.equal(Cu.evalInSandbox("typeof C2.classes", sb1), 'undefined');
+  // non-chrome accessing own Components: shouldn't exist.
+  Assert.equal(Cu.evalInSandbox("typeof Components", sb1), 'undefined');
 
   // chrome accessing chrome
-  sb3.C = Components;
-  rv = Cu.evalInSandbox("C.utils", sb3);
+  sb2.C = Components;
+  rv = Cu.evalInSandbox("C.utils", sb2);
   Assert.equal(rv, Cu);
-
-  // non-chrome cross origin
-  sb4.C2 = C2;
-  checkThrows("C2.interfaces", sb4);
-  checkThrows("C2.utils", sb4);
-  checkThrows("C2.classes", sb4);
 }
 
 function checkThrows(expression, sb) {
   var result = Cu.evalInSandbox('(function() { try { ' + expression + '; return "allowed"; } catch (e) { return e.toString(); }})();', sb);
   Assert.ok(!!/denied/.exec(result));
 }

--- a/layout/forms/test/test_bug348236.html
+++ b/layout/forms/test/test_bug348236.html
@@ -33,17 +33,16 @@ https://bugzilla.mozilla.org/show_bug.cg
 <script type="text/javascript">
 
   /** Test for Bug 348236 **/
 
 SimpleTest.waitForExplicitFinish()
 addLoadEvent(function test() {
 
     var
-        CI = SpecialPowers.Components.interfaces,
         WinUtils = SpecialPowers.getDOMWindowUtils(window),
         sec = netscape.security,
         eSelect = $("eSelect"),
         timeout = 0 // Choose a larger value like 500 ms if you want to see what's happening.
 
     function keypressOnSelect(key) {
         eSelect.focus();
         synthesizeKey(key.key, {altKey: key.altKey});