Bug 1487249 - Part 3: Add the WindowGlobal actor representing a singl…

…e window global, r=bzbarsky

This actor can be used for communicating with individual frames, without
depending on walking the tree in the content process.

This is not yet complete. No tests have been written for it, the
WindowGlobalParent objects need to be exposed to chrome JS, and a form of JS
actors should be installed under them.

In addition, BrowsingContextChrome objects should be updated to allow access to
the current WindowGlobalParent in that context.

Differential Revision: https://phabricator.services.mozilla.com/D4623

dom/base/nsDocument.cpp

@@ -271,6 +271,8 @@
 
 #include "mozilla/DocLoadingTimelineMarker.h"
 
+#include "mozilla/dom/WindowGlobalChild.h"
+
 #include "nsISpeculativeConnect.h"
 
 #include "mozilla/MediaManager.h"
@@ -2897,6 +2899,13 @@ void nsIDocument::SetDocumentURI(nsIURI* aURI) {
   if (!equalBases) {
     RefreshLinkHrefs();
   }
+
+  // Tell our WindowGlobalParent that the document's URI has been changed.
+  nsPIDOMWindowInner* inner = GetInnerWindow();
+  WindowGlobalChild* wgc = inner ? inner->GetWindowGlobalChild() : nullptr;
+  if (wgc) {
+    Unused << wgc->SendUpdateDocumentURI(mDocumentURI);
+  }
 }
 
 static void GetFormattedTimeString(PRTime aTime,

dom/base/nsGlobalWindowInner.cpp

@@ -260,6 +260,8 @@
 #include "mozilla/dom/ClientSource.h"
 #include "mozilla/dom/ClientState.h"
 
+#include "mozilla/dom/WindowGlobalChild.h"
+
 // Apple system headers seem to have a check() macro.  <sigh>
 #ifdef check
 class nsIScriptTimeoutHandler;
@@ -1266,6 +1268,11 @@ void nsGlobalWindowInner::FreeInnerObjects(bool aForDocumentOpen) {
     }
   }
 
+  if (mWindowGlobalChild && !mWindowGlobalChild->IsClosed()) {
+    mWindowGlobalChild->Send__delete__(mWindowGlobalChild);
+  }
+  mWindowGlobalChild = nullptr;
+
   mIntlUtils = nullptr;
 }
 
@@ -1635,6 +1642,15 @@ void nsGlobalWindowInner::InnerSetNewDocument(JSContext* aCx,
   // out of sync.
   ClearDocumentDependentSlots(aCx);
 
+  // FIXME: Currently, devtools can crete a fallback webextension window global
+  // in the content process which does not have a corresponding TabChild actor.
+  // This means we have no actor to be our parent. (Bug 1498293)
+  MOZ_DIAGNOSTIC_ASSERT(!mWindowGlobalChild,
+                        "Shouldn't have created WindowGlobalChild yet!");
+  if (XRE_IsParentProcess() || mTabChild) {
+    mWindowGlobalChild = WindowGlobalChild::Create(this);
+  }
+
 #ifdef DEBUG
   mLastOpenedURI = aDocument->GetDocumentURI();
 #endif

dom/base/nsPIDOMWindow.h

@@ -68,6 +68,7 @@ class ServiceWorker;
 class ServiceWorkerDescriptor;
 class Timeout;
 class TimeoutManager;
+class WindowGlobalChild;
 class CustomElementRegistry;
 enum class CallerType : uint32_t;
 }  // namespace dom
@@ -378,6 +379,10 @@ class nsPIDOMWindowInner : public mozIDOMWindow {
     return mDoc;
   }
 
+  mozilla::dom::WindowGlobalChild* GetWindowGlobalChild() {
+    return mWindowGlobalChild;
+  }
+
   virtual PopupControlState GetPopupControlState() const = 0;
 
   // Determine if the window is suspended or frozen.  Outer windows
@@ -695,6 +700,12 @@ class nsPIDOMWindowInner : public mozIDOMWindow {
   // also set as permissions, but it could happen that we need to access them
   // synchronously in this context, and for this, we need a copy here.
   nsTArray<nsCString> mStorageAccessGranted;
+
+  // The WindowGlobalChild actor for this window.
+  //
+  // This will be non-null during the full lifetime of the window, initialized
+  // during SetNewDocument, and cleared during FreeInnerObjects.
+  RefPtr<mozilla::dom::WindowGlobalChild> mWindowGlobalChild;
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsPIDOMWindowInner, NS_PIDOMWINDOWINNER_IID)

dom/ipc/ContentChild.cpp

@@ -890,9 +890,6 @@ nsresult ContentChild::ProvideWindowCommon(
   TabContext newTabContext = aTabOpener ? *aTabOpener : TabContext();
   RefPtr<TabChild> newChild =
       new TabChild(this, tabId, tabGroup, newTabContext, aChromeFlags);
-  if (NS_FAILED(newChild->Init(aParent))) {
-    return NS_ERROR_ABORT;
-  }
 
   if (aTabOpener) {
     MOZ_ASSERT(ipcContext->type() == IPCTabContext::TPopupIPCTabContext);
@@ -908,6 +905,12 @@ nsresult ContentChild::ProvideWindowCommon(
       RefPtr<TabChild>(newChild).forget().take(), tabId, TabId(0), *ipcContext,
       aChromeFlags, GetID(), IsForBrowser());
 
+  // Now that |newChild| has had its IPC link established, call |Init| to set it
+  // up.
+  if (NS_FAILED(newChild->Init(aParent))) {
+    return NS_ERROR_ABORT;
+  }
+
   nsCOMPtr<nsPIDOMWindowInner> parentTopInnerWindow;
   if (aParent) {
     nsCOMPtr<nsPIDOMWindowOuter> parentTopWindow =

dom/ipc/DOMTypes.ipdlh

@@ -26,6 +26,8 @@ using CSSSize from "Units.h";
 using mozilla::LayoutDeviceIntPoint from "Units.h";
 using hal::ScreenOrientation from "mozilla/HalScreenConfiguration.h";
 using mozilla::gfx::SurfaceFormat from "mozilla/gfx/Types.h";
+using refcounted class nsIPrincipal from "mozilla/dom/PermissionMessageUtils.h";
+using mozilla::dom::BrowsingContextId from "mozilla/dom/ipc/IdType.h";
 
 
 namespace mozilla {
@@ -183,5 +185,11 @@ struct PerformanceInfo
   CategoryDispatch[] items;
 };
 
+struct WindowGlobalInit
+{
+  nsIPrincipal principal;
+  BrowsingContextId browsingContextId;
+};
+
 } // namespace dom
 } // namespace mozilla

dom/ipc/PBrowser.ipdl

@@ -18,6 +18,7 @@ include protocol PParentToChildStream;
 include protocol PFileDescriptorSet;
 include protocol PIPCBlobInputStream;
 include protocol PPaymentRequest;
+include protocol PWindowGlobal;
 
 include DOMTypes;
 include IPCBlob;
@@ -86,6 +87,7 @@ using class mozilla::NativeEventData from "ipc/nsGUIEventIPC.h";
 using mozilla::FontRange from "ipc/nsGUIEventIPC.h";
 using mozilla::a11y::IAccessibleHolder from "mozilla/a11y/IPCTypes.h";
 using mozilla::OriginAttributes from "mozilla/ipc/BackgroundUtils.h";
+using mozilla::dom::BrowsingContextId from "mozilla/dom/ipc/IdType.h";
 
 namespace mozilla {
 namespace dom {
@@ -118,6 +120,7 @@ nested(upto inside_cpow) sync protocol PBrowser
     manages PIndexedDBPermissionRequest;
     manages PPluginWidget;
     manages PPaymentRequest;
+    manages PWindowGlobal;
 
 both:
     async AsyncMessage(nsString aMessage, CpowEntry[] aCpows,
@@ -144,6 +147,12 @@ parent:
 
     async PPaymentRequest();
 
+    /**
+     * Construct a new WindowGlobal actor for a window global in the given
+     * BrowsingContext and with the given principal.
+     */
+    async PWindowGlobal(WindowGlobalInit init);
+
     /**
      * Sends an NS_NATIVE_CHILD_OF_SHAREABLE_WINDOW to be adopted by the
      * widget's shareable window on the chrome side. Only used on Windows.

dom/ipc/PWindowGlobal.ipdl

@@ -0,0 +1,35 @@
+/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 8 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+include protocol PBrowser;
+include protocol PInProcess;
+
+include DOMTypes;
+
+using refcounted class nsIURI from "mozilla/ipc/URIUtils.h";
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * A PWindowGlobal actor has a lifetime matching that of a single Window Global,
+ * specifically a |nsGlobalWindowInner|. These actors will form a parent/child
+ * link either between the chrome/content process, or will be in-process, for
+ * documents which are loaded in the chrome process.
+ */
+async protocol PWindowGlobal
+{
+  manager PBrowser or PInProcess;
+
+parent:
+  /// Update the URI of the document in this WindowGlobal.
+  async UpdateDocumentURI(nsIURI aUri);
+
+  async __delete__();
+};
+
+} // namespace dom
+} // namespace mozilla

dom/ipc/TabChild.cpp

@@ -122,6 +122,7 @@
 #include "mozilla/Telemetry.h"
 #include "nsDocShellLoadState.h"
 #include "nsWebBrowser.h"
+#include "mozilla/dom/WindowGlobalChild.h"
 
 #ifdef XP_WIN
 #include "mozilla/plugins/PluginWidgetChild.h"
@@ -3137,6 +3138,17 @@ bool TabChild::DeallocPPaymentRequestChild(PPaymentRequestChild* actor) {
   return true;
 }
 
+PWindowGlobalChild* TabChild::AllocPWindowGlobalChild(const WindowGlobalInit&) {
+  MOZ_CRASH("We should never be manually allocating PWindowGlobalChild actors");
+  return nullptr;
+}
+
+bool TabChild::DeallocPWindowGlobalChild(PWindowGlobalChild* aActor) {
+  // This reference was added in WindowGlobalChild::Create.
+  static_cast<WindowGlobalChild*>(aActor)->Release();
+  return true;
+}
+
 ScreenIntSize TabChild::GetInnerSize() {
   LayoutDeviceIntSize innerSize =
       RoundedToInt(mUnscaledInnerSize * mPuppetWidget->GetDefaultScale());

dom/ipc/TabChild.h

@@ -657,6 +657,11 @@ class TabChild final : public TabChildBase,
  protected:
   virtual ~TabChild();
 
+  virtual PWindowGlobalChild* AllocPWindowGlobalChild(
+      const WindowGlobalInit& aInit) override;
+
+  virtual bool DeallocPWindowGlobalChild(PWindowGlobalChild* aActor) override;
+
   virtual mozilla::ipc::IPCResult RecvDestroy() override;
 
   virtual mozilla::ipc::IPCResult RecvSetDocShellIsActive(

dom/ipc/TabParent.cpp

@@ -100,6 +100,7 @@
 #include "ProcessPriorityManager.h"
 #include "nsString.h"
 #include "IHistory.h"
+#include "mozilla/dom/WindowGlobalParent.h"
 
 #ifdef XP_WIN
 #include "mozilla/plugins/PluginWidgetParent.h"
@@ -988,6 +989,24 @@ bool TabParent::DeallocPIndexedDBPermissionRequestParent(
       aActor);
 }
 
+IPCResult TabParent::RecvPWindowGlobalConstructor(
+    PWindowGlobalParent* aActor, const WindowGlobalInit& aInit) {
+  static_cast<WindowGlobalParent*>(aActor)->Init();
+  return IPC_OK();
+}
+
+PWindowGlobalParent* TabParent::AllocPWindowGlobalParent(
+    const WindowGlobalInit& aInit) {
+  // Reference freed in DeallocPWindowGlobalParent.
+  return do_AddRef(new WindowGlobalParent(aInit, /* inproc */ false)).take();
+}
+
+bool TabParent::DeallocPWindowGlobalParent(PWindowGlobalParent* aActor) {
+  // Free reference from AllocPWindowGlobalParent.
+  static_cast<WindowGlobalParent*>(aActor)->Release();
+  return true;
+}
+
 void TabParent::SendMouseEvent(const nsAString& aType, float aX, float aY,
                                int32_t aButton, int32_t aClickCount,
                                int32_t aModifiers,

dom/ipc/TabParent.h

@@ -305,6 +305,14 @@ class TabParent final : public PBrowserParent,
    */
   a11y::DocAccessibleParent* GetTopLevelDocAccessible() const;
 
+  virtual PWindowGlobalParent* AllocPWindowGlobalParent(
+      const WindowGlobalInit& aInit) override;
+
+  virtual bool DeallocPWindowGlobalParent(PWindowGlobalParent* aActor) override;
+
+  virtual mozilla::ipc::IPCResult RecvPWindowGlobalConstructor(
+      PWindowGlobalParent* aActor, const WindowGlobalInit& aInit) override;
+
   void LoadURL(nsIURI* aURI);
 
   void InitRendering();

dom/ipc/WindowGlobalChild.cpp

@@ -0,0 +1,81 @@
+/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 8 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/WindowGlobalChild.h"
+#include "mozilla/ipc/InProcessChild.h"
+#include "mozilla/dom/BrowsingContext.h"
+
+namespace mozilla {
+namespace dom {
+
+WindowGlobalChild::WindowGlobalChild(nsGlobalWindowInner* aWindow, dom::BrowsingContext* aBrowsingContext)
+  : mWindowGlobal(aWindow)
+  , mBrowsingContext(aBrowsingContext)
+  , mIPCClosed(false)
+{
+}
+
+already_AddRefed<WindowGlobalChild>
+WindowGlobalChild::Create(nsGlobalWindowInner* aWindow)
+{
+  nsCOMPtr<nsIPrincipal> principal = aWindow->GetPrincipal();
+  MOZ_ASSERT(principal);
+
+  RefPtr<nsDocShell> docshell = nsDocShell::Cast(aWindow->GetDocShell());
+  MOZ_ASSERT(docshell);
+
+  // Initalize our WindowGlobalChild object.
+  RefPtr<dom::BrowsingContext> bc = docshell->GetBrowsingContext();
+  RefPtr<WindowGlobalChild> wgc = new WindowGlobalChild(aWindow, bc);
+
+  WindowGlobalInit init(principal, BrowsingContextId(wgc->BrowsingContext()->Id()));
+
+  // Send the link constructor over PInProcessChild or PBrowser.
+  if (XRE_IsParentProcess()) {
+    InProcessChild* ipc = InProcessChild::Singleton();
+    if (!ipc) {
+      return nullptr;
+    }
+
+    // Note: ref is released in DeallocPWindowGlobalChild
+    ipc->SendPWindowGlobalConstructor(do_AddRef(wgc).take(), init);
+  } else {
+    RefPtr<TabChild> tabChild = TabChild::GetFrom(static_cast<mozIDOMWindow*>(aWindow));
+    MOZ_ASSERT(tabChild);
+
+    // Note: ref is released in DeallocPWindowGlobalChild
+    tabChild->SendPWindowGlobalConstructor(do_AddRef(wgc).take(), init);
+  }
+
+  return wgc.forget();
+}
+
+already_AddRefed<WindowGlobalParent>
+WindowGlobalChild::GetOtherSide()
+{
+  if (mIPCClosed) {
+    return nullptr;
+  }
+  IProtocol* otherSide = InProcessChild::ParentActorFor(this);
+  return do_AddRef(static_cast<WindowGlobalParent*>(otherSide));
+}
+
+void
+WindowGlobalChild::ActorDestroy(ActorDestroyReason aWhy)
+{
+  mIPCClosed = true;
+}
+
+WindowGlobalChild::~WindowGlobalChild()
+{
+}
+
+NS_IMPL_CYCLE_COLLECTION(WindowGlobalChild, mWindowGlobal, mBrowsingContext)
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WindowGlobalChild, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WindowGlobalChild, Release)
+
+} // namespace dom
+} // namespace mozilla