diff --git a/dom/security/test/csp/test_reloadInFreshProcess.html b/dom/security/test/csp/test_reloadInFreshProcess.html
index 5abbd3dd1af3..4423b6c92c31 100644
--- a/dom/security/test/csp/test_reloadInFreshProcess.html
+++ b/dom/security/test/csp/test_reloadInFreshProcess.html
@@ -20,16 +20,15 @@
  * Test 2 |                             | "upgrade-insecure-requests" | http
  *
  * Test 1:
- * We load an iframe which uses 'upgrade-insecure-requests' which then
- * opens an "http" window which uses the header "Large-Allocation".
- * We observe that the initial request as well as the "Large-Allocation"
- * request get upgraded to use "https://test1.example.com".
+ * We load an iframe which uses 'upgrade-insecure-requests' which then opens an
+ * "http" window which uses the header "Large-Allocation". We observe that the
+ * request gets upgraded to use "https://test1.example.com".
  *
  * Test 2:
  * We load an iframe which does not use any CSP and opens an "http" window
  * which uses the header "Large-Allocation" as well as a CSP of
- * "upgrade-insecure-requests". We observe that both requests do
- * not get upgraded to https but still use "http://test2.example.com".
+ * "upgrade-insecure-requests". We observe that the request does not get
+ * upgraded to https but still uses "http://test2.example.com".
  */
 
 SimpleTest.waitForExplicitFinish();
@@ -38,7 +37,7 @@ let httpsCounter = 0;
 let httpCounter = 0;
 
 function checkTestComplete() {
-  if (httpsCounter == 2 && httpCounter == 2) {
+  if (httpsCounter == 1 && httpCounter == 1) {
     ok(true, "Frame with CSP caused upgrade; Frame with no CSP caused no upgrade");
     window.URLExaminer.remove();
     SimpleTest.finish();
diff --git a/dom/tests/browser/browser.ini b/dom/tests/browser/browser.ini
index 7ceef1f384db..69a0fd55c834 100644
--- a/dom/tests/browser/browser.ini
+++ b/dom/tests/browser/browser.ini
@@ -56,9 +56,9 @@ support-files =
   beforeunload_test_page.html
 run-if = e10s
 [browser_largeAllocation_win32.js]
-skip-if = fission || !e10s || os != "win" || processor != "x86" # Large-Allocation requires e10s
+skip-if = fission || !e10s || os != "win" || processor != "x86" # Large-Allocation requires non-fission e10s
 [browser_largeAllocation_non_win32.js]
-skip-if = fission || !e10s || (os == "win" && (processor == "x86" || processor == "aarch64")) || (verify && debug && (os == 'linux')) || (os == 'linux') || (os == 'mac') || (os == "win" && debug) # Large-Allocation requires e10s # Bug 1336075
+skip-if = fission || !e10s || (os == "win" && processor == "x86") # Large-Allocation requires non-fission e10s
 [browser_localStorage_e10s.js]
 fail-if = fission
 skip-if = !e10s || verify # This is a test of e10s functionality.
diff --git a/dom/tests/browser/helper_largeAllocation.js b/dom/tests/browser/helper_largeAllocation.js
index 0117e8500342..ec5b4b3158e9 100644
--- a/dom/tests/browser/helper_largeAllocation.js
+++ b/dom/tests/browser/helper_largeAllocation.js
@@ -28,26 +28,14 @@ function expectProcessCreated() {
   return promise;
 }
 
-function expectNoProcess() {
-  let os = Services.obs;
-  let topic = "ipc:content-created";
-  function observer() {
-    ok(false, "A process was created!");
-    os.removeObserver(observer, topic);
-  }
-  os.addObserver(observer, topic);
-
-  return () => os.removeObserver(observer, topic);
-}
-
 function getPID(aBrowser) {
-  return ContentTask.spawn(aBrowser, [], () => {
+  return SpecialPowers.spawn(aBrowser, [], () => {
     return Services.appinfo.processID;
   });
 }
 
 function getInLAProc(aBrowser) {
-  return ContentTask.spawn(aBrowser, [], () => {
+  return SpecialPowers.spawn(aBrowser, [], () => {
     return Services.appinfo.remoteType == "webLargeAllocation";
   });
 }
@@ -79,13 +67,17 @@ async function largeAllocSuccessTests() {
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    let epc = expectProcessCreated();
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    let ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
+
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
     // Wait for the new process to be created
-    await epc;
+    await ready;
 
     let pid2 = await getPID(aBrowser);
 
@@ -104,10 +96,7 @@ async function largeAllocSuccessTests() {
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    // Fail the test if we create a process
-    let stopExpectNoProcess = expectNoProcess();
-
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       // eslint-disable-next-line no-unsanitized/property
       content.document.body.innerHTML = `<iframe src='${TEST_URI}'></iframe>`;
 
@@ -123,8 +112,6 @@ async function largeAllocSuccessTests() {
 
     is(pid1, pid2, "The PID should not have changed");
     is(false, await getInLAProc(aBrowser));
-
-    stopExpectNoProcess();
   });
 
   // If you have an opener cross process navigation shouldn't work
@@ -135,62 +122,51 @@ async function largeAllocSuccessTests() {
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    // Fail the test if we create a process
-    let stopExpectNoProcess = expectNoProcess();
-
-    let loaded = ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
+      info(TEST_URI);
       content.document.body.innerHTML = "<button>CLICK ME</button>";
 
       return new Promise(resolve => {
-        content.document.querySelector("button").onclick = e => {
-          let w = content.window.open(TEST_URI, "_blank");
-          w.onload = () => {
-            ok(true, "Window finished loading");
-            w.close();
-            resolve();
-          };
+        let w = content.window.open(TEST_URI, "_blank");
+        w.onload = () => {
+          ok(true, "Window finished loading");
+          w.close();
+          resolve();
         };
       });
     });
 
-    await BrowserTestUtils.synthesizeMouseAtCenter("button", {}, aBrowser);
-
-    await loaded;
-
     let pid2 = await getPID(aBrowser);
 
     is(pid1, pid2, "The PID should not have changed");
     is(false, await getInLAProc(aBrowser));
-
-    stopExpectNoProcess();
   });
 
-  // Load Large-Allocation twice with about:blank load in between
+  // Load Large-Allocation twice with example.com load in between
   await BrowserTestUtils.withNewTab("about:blank", async function(aBrowser) {
     info("Starting test 3");
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    let epc = expectProcessCreated();
+    let ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
-    await epc;
+    await ready;
 
     let pid2 = await getPID(aBrowser);
 
     isnot(pid1, pid2);
     is(true, await getInLAProc(aBrowser));
 
-    await BrowserTestUtils.browserLoaded(aBrowser);
-
-    await ContentTask.spawn(
-      aBrowser,
-      [],
-      () => (content.document.location = "about:blank")
-    );
+    await SpecialPowers.spawn(aBrowser, [], () => {
+      content.document.location = "http://example.com";
+    });
 
     await BrowserTestUtils.browserLoaded(aBrowser);
 
@@ -198,13 +174,16 @@ async function largeAllocSuccessTests() {
     // load, meaning we're back in a non-fresh process
     is(false, await getInLAProc(aBrowser));
 
-    epc = expectProcessCreated();
+    ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
-    await epc;
+    await ready;
 
     let pid4 = await getPID(aBrowser);
 
@@ -213,30 +192,31 @@ async function largeAllocSuccessTests() {
     is(true, await getInLAProc(aBrowser));
   });
 
-  // Load Large-Allocation then about:blank load, then back button press should load from bfcache.
+  // Load Large-Allocation then example.com load, then back button press should load from bfcache.
   await BrowserTestUtils.withNewTab("about:blank", async function(aBrowser) {
     info("Starting test 4");
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    let epc = expectProcessCreated();
+    let ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
-    await epc;
+    await ready;
 
     let pid2 = await getPID(aBrowser);
 
     isnot(pid1, pid2, "PIDs 1 and 2 should not match");
     is(true, await getInLAProc(aBrowser));
 
-    await BrowserTestUtils.browserLoaded(aBrowser);
-
     // Switch to about:blank, so we can navigate back
-    await ContentTask.spawn(aBrowser, [], () => {
-      content.document.location = "about:blank";
+    await SpecialPowers.spawn(aBrowser, [], () => {
+      content.document.location = "http://example.com";
     });
 
     await BrowserTestUtils.browserLoaded(aBrowser);
@@ -247,15 +227,18 @@ async function largeAllocSuccessTests() {
     // load, meaning we're back in a non-large-allocation process.
     is(false, await getInLAProc(aBrowser));
 
-    epc = expectProcessCreated();
+    ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
 
     // Navigate back to the previous page. As the large alloation process was
     // left, it won't be in bfcache and will have to be loaded fresh.
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.window.history.back();
     });
 
-    await epc;
+    await ready;
 
     let pid4 = await getPID(aBrowser);
 
@@ -276,7 +259,7 @@ async function largeAllocSuccessTests() {
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -287,27 +270,16 @@ async function largeAllocSuccessTests() {
     isnot(pid1, pid2, "PIDs 1 and 2 should not match");
     is(true, await getInLAProc(aBrowser));
 
-    let epc = expectProcessCreated();
+    ready = Promise.all([
+      expectProcessCreated(),
+      BrowserTestUtils.browserLoaded(aBrowser),
+    ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI_2, TEST_URI_2 => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI_2], TEST_URI_2 => {
       content.document.location = TEST_URI_2;
     });
 
-    await epc;
-
-    // We just saw the creation of a new process. This is either the process we
-    // are interested in, or, in a multi-e10s situation, the normal content
-    // process which was created for the normal content to be loaded into as the
-    // browsing context was booted out of the fresh process. If we discover that
-    // this was not a fresh process, we'll need to wait for another process.
-    // Start listening now.
-    epc = expectProcessCreated();
-    if (!(await getInLAProc(aBrowser))) {
-      await epc;
-    } else {
-      epc.catch(() => {});
-      epc.kill();
-    }
+    await ready;
 
     let pid3 = await getPID(aBrowser);
 
@@ -327,7 +299,7 @@ async function largeAllocSuccessTests() {
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -338,11 +310,13 @@ async function largeAllocSuccessTests() {
     isnot(pid1, pid2, "PIDs 1 and 2 should not match");
     is(true, await getInLAProc(aBrowser));
 
-    let stopExpectNoProcess = expectNoProcess();
-
-    await ContentTask.spawn(aBrowser, [], () => {
-      this.__newWindow = content.window.open("about:blank");
-      content.document.location = "about:blank";
+    let promiseTabOpened = BrowserTestUtils.waitForNewTab(
+      gBrowser,
+      "about:blank"
+    );
+    await SpecialPowers.spawn(aBrowser, [], () => {
+      content.window.open("about:blank");
+      content.document.location = "http://example.com";
     });
 
     await BrowserTestUtils.browserLoaded(aBrowser);
@@ -352,12 +326,7 @@ async function largeAllocSuccessTests() {
     is(pid3, pid2, "PIDs 2 and 3 should match");
     is(true, await getInLAProc(aBrowser));
 
-    stopExpectNoProcess();
-
-    await ContentTask.spawn(aBrowser, [], () => {
-      ok(this.__newWindow, "The window should have been stored");
-      this.__newWindow.close();
-    });
+    BrowserTestUtils.removeTab(await promiseTabOpened);
   });
 
   // Opening a window from the large-allocation window should prevent the
@@ -372,7 +341,7 @@ async function largeAllocSuccessTests() {
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -383,17 +352,15 @@ async function largeAllocSuccessTests() {
     isnot(pid1, pid2, "PIDs 1 and 2 should not match");
     is(true, await getInLAProc(aBrowser));
 
-    let stopExpectNoProcess = expectNoProcess();
-
     let firstTab = gBrowser.selectedTab;
     let promiseTabOpened = BrowserTestUtils.waitForNewTab(
       gBrowser,
       "about:blank"
     );
-    await ContentTask.spawn(aBrowser, [], () => {
-      this.__newWindow = content.window.open("about:blank");
+    await SpecialPowers.spawn(aBrowser, [], () => {
+      content.window.open("about:blank");
     });
-    await promiseTabOpened;
+    let newTab = await promiseTabOpened;
 
     if (firstTab != gBrowser.selectedTab) {
       firstTab = await BrowserTestUtils.switchTab(gBrowser, firstTab);
@@ -408,12 +375,7 @@ async function largeAllocSuccessTests() {
     is(pid3, pid2, "PIDs 2 and 3 should match");
     is(true, await getInLAProc(aBrowser));
 
-    stopExpectNoProcess();
-
-    await ContentTask.spawn(aBrowser, [], () => {
-      ok(this.__newWindow, "The window should have been stored");
-      this.__newWindow.close();
-    });
+    BrowserTestUtils.removeTab(newTab);
   });
 
   // Try dragging the tab into a new window when not at the maximum number of
@@ -428,7 +390,7 @@ async function largeAllocSuccessTests() {
       expectProcessCreated(),
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -476,7 +438,7 @@ async function largeAllocSuccessTests() {
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
 
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -493,7 +455,7 @@ async function largeAllocSuccessTests() {
       is(false, await getInLAProc(aBrowser));
 
       let ready = Promise.all([BrowserTestUtils.browserLoaded(aBrowser)]);
-      await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+      await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
         content.document.location = TEST_URI;
       });
       await ready;
@@ -514,10 +476,7 @@ async function largeAllocSuccessTests() {
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    // Fail the test if we create a process
-    let stopExpectNoProcess = expectNoProcess();
-
-    await ContentTask.spawn(aBrowser, [], () => {
+    await SpecialPowers.spawn(aBrowser, [], () => {
       content.document.location = "view-source:http://example.com";
     });
 
@@ -527,8 +486,6 @@ async function largeAllocSuccessTests() {
 
     is(pid1, pid2, "The PID should not have changed");
     is(false, await getInLAProc(aBrowser));
-
-    stopExpectNoProcess();
   });
 
   // Try dragging tab into new window when at the max number of large allocation
@@ -546,7 +503,7 @@ async function largeAllocSuccessTests() {
       expectProcessCreated(),
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -588,7 +545,7 @@ async function largeAllocSuccessTests() {
       expectProcessCreated(),
       BrowserTestUtils.browserLoaded(aBrowser),
     ]);
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -600,7 +557,7 @@ async function largeAllocSuccessTests() {
     is(true, await getInLAProc(aBrowser));
 
     await Promise.all([
-      ContentTask.spawn(aBrowser, null, () => {
+      SpecialPowers.spawn(aBrowser, [], () => {
         content.document.querySelector("#submit").click();
       }),
       BrowserTestUtils.browserLoaded(aBrowser),
@@ -629,10 +586,7 @@ async function largeAllocFailTests() {
     let pid1 = await getPID(aBrowser);
     is(false, await getInLAProc(aBrowser));
 
-    // Fail the test if we create a process
-    let stopExpectNoProcess = expectNoProcess();
-
-    await ContentTask.spawn(aBrowser, TEST_URI, TEST_URI => {
+    await SpecialPowers.spawn(aBrowser, [TEST_URI], TEST_URI => {
       content.document.location = TEST_URI;
     });
 
@@ -642,7 +596,5 @@ async function largeAllocFailTests() {
 
     is(pid1, pid2, "The PID should not have changed");
     is(false, await getInLAProc(aBrowser));
-
-    stopExpectNoProcess();
   });
 }