Bug 1288843: Modify OuterDocAccessible so that ChildCount() and ChildAt(0) resolve RemoteChildDoc(); r=tbsaunde

MozReview-Commit-ID: EsayZhH2nY8

--HG--
extra : rebase_source : decda5eeeebab0ee899cd67d51b0490b54f8ca5f

accessible/generic/OuterDocAccessible.cpp

@@ -173,6 +173,40 @@ OuterDocAccessible::IsAcceptableChild(nsIContent* aEl) const
   return false;
 }
 
+#if defined(XP_WIN)
+
+// On Windows e10s, since we don't cache in the chrome process, these next two
+// functions must be implemented so that we properly cross the chrome-to-content
+// boundary when traversing.
+
+uint32_t
+OuterDocAccessible::ChildCount() const
+{
+  uint32_t result = mChildren.Length();
+  if (!result && RemoteChildDoc()) {
+    result = 1;
+  }
+  return result;
+}
+
+Accessible*
+OuterDocAccessible::GetChildAt(uint32_t aIndex) const
+{
+  Accessible* result = AccessibleWrap::GetChildAt(aIndex);
+  if (result || aIndex) {
+    return result;
+  }
+  // If we are asking for child 0 and GetChildAt doesn't return anything, try
+  // to get the remote child doc and return that instead.
+  ProxyAccessible* remoteChild = RemoteChildDoc();
+  if (!remoteChild) {
+    return nullptr;
+  }
+  return WrapperFor(remoteChild);
+}
+
+#endif // defined(XP_WIN)
+
 ProxyAccessible*
 OuterDocAccessible::RemoteChildDoc() const
 {

accessible/generic/OuterDocAccessible.h

@@ -40,6 +40,11 @@ public:
   virtual bool RemoveChild(Accessible* aAccessible) override;
   virtual bool IsAcceptableChild(nsIContent* aEl) const override;
 
+#if defined(XP_WIN)
+  virtual uint32_t ChildCount() const override;
+  virtual Accessible* GetChildAt(uint32_t aIndex) const override;
+#endif // defined(XP_WIN)
+
 protected:
   virtual ~OuterDocAccessible() override;
 };
@@ -53,4 +58,4 @@ Accessible::AsOuterDoc()
 } // namespace a11y
 } // namespace mozilla
 
-#endif  
+#endif