Bug 1543298 part 1: Add a stub AccessibleWrap used in a Windows content process for an embedded document residing in another content process. r=eeejay

For an out-of-process iframe, we need to be able to return a remote embedder accessible as a child of an OuterDocAccessible.
For parent process OuterDocAccessibles, we use the ProxyAccessible for the embedded document.
In the case of out-of-process iframes, there is no ProxyAccessible for the embedded document, since the iframe is in a content process and ProxyAccessibles only exist in the parent process.
Like ProxyAccessibleWrap, the only real method that gets called is GetNativeInterface, which returns a COM proxy for the document.

Differential Revision: https://phabricator.services.mozilla.com/D32278

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

accessible/windows/ProxyWrappers.h

@@ -8,7 +8,7 @@
 #ifndef MOZILLA_A11Y_ProxyWrappers_h
 #define MOZILLA_A11Y_ProxyWrappers_h
 
-#include "HyperTextAccessible.h"
+#include "HyperTextAccessibleWrap.h"
 
 namespace mozilla {
 namespace a11y {
@@ -79,6 +79,36 @@ inline ProxyAccessible* HyperTextProxyFor(T* aWrapper) {
   return wrapper->IsProxy() ? wrapper->Proxy() : nullptr;
 }
 
+/**
+ * Stub AccessibleWrap used in a content process for an embedded document
+ * residing in another content process.
+ * There is no ProxyAccessible here, since those only exist in the parent
+ * process. However, like ProxyAccessibleWrap, the only real method that
+ * gets called is GetNativeInterface, which returns a COM proxy for the
+ * document.
+ */
+class RemoteIframeDocProxyAccessibleWrap : public HyperTextAccessibleWrap {
+ public:
+  explicit RemoteIframeDocProxyAccessibleWrap(IDispatch* aCOMProxy)
+      : HyperTextAccessibleWrap(nullptr, nullptr), mCOMProxy(aCOMProxy) {
+    mType = eProxyType;
+    mBits.proxy = nullptr;
+  }
+
+  virtual void Shutdown() override {
+    mStateFlags |= eIsDefunct;
+    mCOMProxy = nullptr;
+  }
+
+  virtual void GetNativeInterface(void** aOutAccessible) override {
+    RefPtr<IDispatch> addRefed = mCOMProxy;
+    addRefed.forget(aOutAccessible);
+  }
+
+ private:
+  RefPtr<IDispatch> mCOMProxy;
+};
+
 }  // namespace a11y
 }  // namespace mozilla
 

accessible/windows/moz.build

@@ -6,3 +6,6 @@
 
 DIRS += ['msaa', 'ia2', 'sdn', 'uia']
 
+EXPORTS.mozilla.a11y += [
+    'ProxyWrappers.h',
+]