Bug 1534267 - Make BrowserBridgeParent* available via TabParent. r=rhunt

Differential Revision: https://phabricator.services.mozilla.com/D22972

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

dom/ipc/BrowserBridgeParent.cpp

@@ -17,7 +17,11 @@ namespace dom {
 
 BrowserBridgeParent::BrowserBridgeParent() : mIPCOpen(false) {}
 
-BrowserBridgeParent::~BrowserBridgeParent() {}
+BrowserBridgeParent::~BrowserBridgeParent() {
+  if (mTabParent) {
+    mTabParent->mBrowserBridgeParent = nullptr;
+  }
+}
 
 nsresult BrowserBridgeParent::Init(const nsString& aPresentationURL,
                                    const nsString& aRemoteType) {
@@ -53,7 +57,7 @@ nsresult BrowserBridgeParent::Init(const nsString& aPresentationURL,
   // Construct the TabParent object for our subframe.
   uint32_t chromeFlags = 0;
   RefPtr<TabParent> tabParent(
-      new TabParent(constructorSender, tabId, tabContext, chromeFlags));
+      new TabParent(constructorSender, tabId, tabContext, chromeFlags, this));
 
   PBrowserParent* browser = constructorSender->SendPBrowserConstructor(
       // DeallocPBrowserParent() releases this ref.

dom/ipc/TabParent.cpp

@@ -144,7 +144,8 @@ NS_IMPL_ISUPPORTS(TabParent, nsITabParent, nsIAuthPromptProvider,
                   nsISupportsWeakReference)
 
 TabParent::TabParent(ContentParent* aManager, const TabId& aTabId,
-                     const TabContext& aContext, uint32_t aChromeFlags)
+                     const TabContext& aContext, uint32_t aChromeFlags,
+                     BrowserBridgeParent* aBrowserBridgeParent)
     : TabContext(aContext),
       mFrameElement(nullptr),
       mContentCache(*this),
@@ -162,6 +163,7 @@ TabParent::TabParent(ContentParent* aManager, const TabId& aTabId,
       mIsDestroyed(false),
       mChromeFlags(aChromeFlags),
       mDragValid(false),
+      mBrowserBridgeParent(aBrowserBridgeParent),
       mTabId(aTabId),
       mCreatingWindow(false),
       mCursor(eCursorInvalid),
@@ -2320,6 +2322,10 @@ RenderFrame* TabParent::GetRenderFrame() {
   return &mRenderFrame;
 }
 
+BrowserBridgeParent* TabParent::GetBrowserBridgeParent() const {
+  return mBrowserBridgeParent;
+}
+
 mozilla::ipc::IPCResult TabParent::RecvRequestIMEToCommitComposition(
     const bool& aCancel, bool* aIsCommitted, nsString* aCommittedString) {
   nsCOMPtr<nsIWidget> widget = GetWidget();

dom/ipc/TabParent.h

@@ -72,6 +72,7 @@ class ClonedMessageData;
 class ContentParent;
 class Element;
 class DataTransfer;
+class BrowserBridgeParent;
 
 namespace ipc {
 class StructuredCloneData;
@@ -88,6 +89,7 @@ class TabParent final : public PBrowserParent,
   typedef mozilla::dom::ClonedMessageData ClonedMessageData;
 
   friend class PBrowserParent;
+  friend class BrowserBridgeParent;  // for clearing mBrowserBridgeParent
 
   virtual ~TabParent();
 
@@ -101,7 +103,8 @@ class TabParent final : public PBrowserParent,
   NS_DECL_NSIDOMEVENTLISTENER
 
   TabParent(ContentParent* aManager, const TabId& aTabId,
-            const TabContext& aContext, uint32_t aChromeFlags);
+            const TabContext& aContext, uint32_t aChromeFlags,
+            BrowserBridgeParent* aBrowserBridgeParent = nullptr);
 
   Element* GetOwnerElement() const { return mFrameElement; }
   already_AddRefed<nsPIDOMWindowOuter> GetParentWindowOuter();
@@ -570,6 +573,10 @@ class TabParent final : public PBrowserParent,
 
   layout::RenderFrame* GetRenderFrame();
 
+  // Returns the BrowserBridgeParent if this TabParent is for an out-of-process
+  // iframe and nullptr otherwise.
+  BrowserBridgeParent* GetBrowserBridgeParent() const;
+
   mozilla::ipc::IPCResult RecvEnsureLayersConnected(
       CompositorOptions* aCompositorOptions);
 
@@ -704,6 +711,12 @@ class TabParent final : public PBrowserParent,
   // The root browsing context loaded in this TabParent.
   RefPtr<CanonicalBrowsingContext> mBrowsingContext;
 
+  // Pointer back to BrowserBridgeParent if there is one associated with
+  // this TabParent. This is non-owning to avoid cycles and is managed
+  // by the BrowserBridgeParent instance, which has the strong reference
+  // to this TabParent.
+  BrowserBridgeParent* mBrowserBridgeParent;
+
   TabId mTabId;
 
   // When loading a new tab or window via window.open, the child is