Bug 1542782 - Expose currentRemoteType on CanonicalBrowsingContext, r=farre

Differential Revision: https://phabricator.services.mozilla.com/D26550

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

docshell/base/CanonicalBrowsingContext.cpp

@@ -65,6 +65,23 @@ ContentParent* CanonicalBrowsingContext::GetContentParent() const {
   return cpm->GetContentProcessById(ContentParentId(mProcessId));
 }
 
+void CanonicalBrowsingContext::GetCurrentRemoteType(nsAString& aRemoteType,
+                                                    ErrorResult& aRv) const {
+  // If we're in the parent process, dump out the void string.
+  if (mProcessId == 0) {
+    aRemoteType.Assign(VoidString());
+    return;
+  }
+
+  ContentParent* cp = GetContentParent();
+  if (!cp) {
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return;
+  }
+
+  aRemoteType.Assign(cp->GetRemoteType());
+}
+
 void CanonicalBrowsingContext::GetWindowGlobals(
     nsTArray<RefPtr<WindowGlobalParent>>& aWindows) {
   aWindows.SetCapacity(mWindowGlobals.Count());

docshell/base/CanonicalBrowsingContext.h

@@ -36,6 +36,8 @@ class CanonicalBrowsingContext final : public BrowsingContext {
   uint64_t OwnerProcessId() const { return mProcessId; }
   ContentParent* GetContentParent() const;
 
+  void GetCurrentRemoteType(nsAString& aRemoteType, ErrorResult& aRv) const;
+
   void SetOwnerProcessId(uint64_t aProcessId) { mProcessId = aProcessId; }
 
   void GetWindowGlobals(nsTArray<RefPtr<WindowGlobalParent>>& aWindows);

dom/chrome-webidl/BrowsingContext.webidl

@@ -33,6 +33,12 @@ interface CanonicalBrowsingContext : BrowsingContext {
 
   readonly attribute WindowGlobalParent? currentWindowGlobal;
 
+  // XXX(nika): This feels kinda hacky, but will do for now while we don't
+  // synchronously create WindowGlobalParent. It can throw if somehow the
+  // content process has died.
+  [Throws]
+  readonly attribute DOMString? currentRemoteType;
+
   void notifyStartDelayedAutoplayMedia();
 };