Bug 1622420 - Set the current WindowContext for BrowsingContexts newly created over IPC. r=farre

Differential Revision: https://phabricator.services.mozilla.com/D68572

--HG--
extra : moz-landing-system : lando

docshell/base/BrowsingContext.cpp

@@ -646,6 +646,10 @@ void BrowsingContext::RegisterWindowContext(WindowContext* aWindow) {
   MOZ_ASSERT(!mWindowContexts.Contains(aWindow),
              "WindowContext already registered!");
   mWindowContexts.AppendElement(aWindow);
+  if (aWindow->InnerWindowId() == GetCurrentInnerWindowId()) {
+    MOZ_ASSERT(aWindow->GetBrowsingContext() == this);
+    mCurrentWindowContext = aWindow;
+  }
 }
 
 void BrowsingContext::UnregisterWindowContext(WindowContext* aWindow) {

docshell/test/browser/Bug1622420Child.jsm

@@ -0,0 +1,11 @@
+var EXPORTED_SYMBOLS = ["Bug1622420Child"];
+
+class Bug1622420Child extends JSWindowActorChild {
+  receiveMessage(msg) {
+    switch (msg.name) {
+      case "hasWindowContextForTopBC":
+        return !!this.browsingContext.top.currentWindowContext;
+    }
+    return null;
+  }
+}

docshell/test/browser/browser.ini

@@ -82,6 +82,10 @@ support-files =
 [browser_bug1347823.js]
 [browser_bug134911.js]
 [browser_bug1415918_beforeunload_options.js]
+[browser_bug1622420.js]
+support-files =
+  file_bug1622420.html
+  Bug1622420Child.jsm
 [browser_bug234628-1.js]
 [browser_bug234628-10.js]
 [browser_bug234628-11.js]

docshell/test/browser/browser_bug1622420.js

@@ -0,0 +1,30 @@
+const ACTOR = "Bug1622420";
+
+add_task(async function test() {
+  let base = getRootDirectory(gTestPath).slice(0, -1);
+  ChromeUtils.registerWindowActor(ACTOR, {
+    allFrames: true,
+    child: {
+      moduleURI: `${base}/Bug1622420Child.jsm`,
+    },
+  });
+
+  registerCleanupFunction(async () => {
+    gBrowser.removeTab(tab);
+
+    ChromeUtils.unregisterWindowActor(ACTOR);
+  });
+
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "http://example.org/browser/docshell/test/browser/file_bug1622420.html"
+  );
+  let childBC = tab.linkedBrowser.browsingContext.children[0];
+  let success = await childBC.currentWindowGlobal
+    .getActor(ACTOR)
+    .sendQuery("hasWindowContextForTopBC");
+  ok(
+    success,
+    "Should have a WindowContext for the top BrowsingContext in the process of a child BrowsingContext"
+  );
+});

docshell/test/browser/file_bug1622420.html

@@ -0,0 +1 @@
+<iframe src="http://example.com/"></iframe>

dom/chrome-webidl/BrowsingContext.webidl

@@ -35,6 +35,8 @@ interface BrowsingContext {
 
   readonly attribute WindowProxy? window;
 
+  readonly attribute WindowContext? currentWindowContext;
+
   attribute [TreatNullAs=EmptyString] DOMString customUserAgent;
 
   /**