Bug 1362866 - Get rid of MozTabChildNotReady event and all of its required infrastructure. r=billm

This event is no longer necessary, since checking nsITabParent.hasPresented is enough to know
if we need to blank out the tab or not.

MozReview-Commit-ID: 445XMqhorxC

--HG--
extra : rebase_source : 1a05de827502c409d979a621471978b08ce39fb2

dom/ipc/ContentParent.cpp

@@ -4263,23 +4263,6 @@ ContentParent::RecvNotifyTabDestroying(const TabId& aTabId,
   return IPC_OK();
 }
 
-mozilla::ipc::IPCResult
-ContentParent::RecvTabChildNotReady(const TabId& aTabId)
-{
-  ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  RefPtr<TabParent> tp =
-    cpm->GetTopLevelTabParentByProcessAndTabId(this->ChildID(), aTabId);
-
-  if (!tp) {
-    NS_WARNING("Couldn't find TabParent for TabChildNotReady message.");
-    return IPC_OK();
-  }
-
-  tp->DispatchTabChildNotReadyEvent();
-
-  return IPC_OK();
-}
-
 nsTArray<TabContext>
 ContentParent::GetManagedTabContext()
 {

dom/ipc/ContentParent.h

@@ -493,8 +493,6 @@ public:
   virtual mozilla::ipc::IPCResult RecvNotifyTabDestroying(const TabId& aTabId,
                                                           const ContentParentId& aCpId) override;
 
-  virtual mozilla::ipc::IPCResult RecvTabChildNotReady(const TabId& aTabId) override;
-
   nsTArray<TabContext> GetManagedTabContext();
 
   virtual POfflineCacheUpdateParent*

dom/ipc/PContent.ipdl

@@ -930,9 +930,6 @@ parent:
      */
     async NotifyTabDestroying(TabId tabId,
                               ContentParentId cpId);
-
-    async TabChildNotReady(TabId tabId);
-
     /**
      * Starts an offline application cache update.
      * @param manifestURI

dom/ipc/PProcessHangMonitor.ipdl

@@ -33,7 +33,6 @@ protocol PProcessHangMonitor
 parent:
   async HangEvidence(HangData data);
   async ClearHang();
-  async Ready();
 
 child:
   async TerminateScript();

dom/ipc/ProcessHangMonitor.cpp

@@ -12,7 +12,6 @@
 
 #include "mozilla/Atomics.h"
 #include "mozilla/BackgroundHangMonitor.h"
-#include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/ScriptSettings.h"
@@ -193,8 +192,6 @@ public:
     mDumpId.Truncate();
   }
 
-  void DispatchTabChildNotReady(TabId aTabId);
-
 private:
   ~HangMonitoredProcess() = default;
 
@@ -214,7 +211,6 @@ public:
 
   void Bind(Endpoint<PProcessHangMonitorParent>&& aEndpoint);
 
-  mozilla::ipc::IPCResult RecvReady() override;
   mozilla::ipc::IPCResult RecvHangEvidence(const HangData& aHangData) override;
   mozilla::ipc::IPCResult RecvClearHang() override;
 
@@ -249,8 +245,6 @@ private:
 
   void ClearHangNotification();
 
-  void DispatchTabChildNotReady(TabId aTabId);
-
   void ForcePaintOnThread(TabId aTabId, uint64_t aLayerObserverEpoch);
 
   void ShutdownOnThread();
@@ -260,12 +254,6 @@ private:
   // This field is read-only after construction.
   bool mReportHangs;
 
-  // This field is only accessed on the hang thread. Inits to
-  // false, and will flip to true once the HangMonitorChild is
-  // constructed in the child process, and sends a message saying
-  // so.
-  bool mReady;
-
   // This field is only accessed on the hang thread.
   bool mIPCOpen;
 
@@ -339,11 +327,6 @@ HangMonitorChild::InterruptCallback()
     if (tabChild) {
       js::AutoAssertNoContentJS nojs(mContext);
       tabChild->ForcePaint(forcePaintEpoch);
-    } else {
-      auto cc = ContentChild::GetSingleton();
-      if (cc) {
-        cc->SendTabChildNotReady(forcePaintTab);
-      }
     }
   }
 }
@@ -449,8 +432,6 @@ HangMonitorChild::Bind(Endpoint<PProcessHangMonitorChild>&& aEndpoint)
 
   DebugOnly<bool> ok = aEndpoint.Bind(this);
   MOZ_ASSERT(ok);
-
-  Unused << SendReady();
 }
 
 void
@@ -571,7 +552,6 @@ HangMonitorChild::ClearHangAsync()
 
 HangMonitorParent::HangMonitorParent(ProcessHangMonitor* aMonitor)
  : mHangMonitor(aMonitor),
-   mReady(false),
    mIPCOpen(true),
    mMonitor("HangMonitorParent lock"),
    mShutdownDone(false),
@@ -651,38 +631,13 @@ HangMonitorParent::ForcePaint(dom::TabParent* aTab, uint64_t aLayerObserverEpoch
   }
 }
 
-void
-HangMonitorParent::DispatchTabChildNotReady(TabId aTabId)
-{
-  MOZ_RELEASE_ASSERT(NS_IsMainThread());
-  if (!mProcess) {
-    return;
-  }
-
-  mProcess->DispatchTabChildNotReady(aTabId);
-}
-
 void
 HangMonitorParent::ForcePaintOnThread(TabId aTabId, uint64_t aLayerObserverEpoch)
 {
   MOZ_RELEASE_ASSERT(MessageLoop::current() == MonitorLoop());
 
   if (mIPCOpen) {
-    if (mReady) {
-      Unused << SendForcePaint(aTabId, aLayerObserverEpoch);
-    } else {
-      // We've never heard from the HangMonitorChild before, so
-      // it's either not finished setting up, or has only recently
-      // finished setting up. In either case, we're dealing with
-      // a new content process that probably hasn't had time to
-      // get the ContentChild, let alone the TabChild for aTabId,
-      // set up, and so attempting to force paint on the non-existant
-      // TabChild is not going to work. Instead, we tell the main
-      // thread that we're waiting on a TabChild to be created.
-      NS_DispatchToMainThread(
-        mMainThreadTaskFactory.NewRunnableMethod(
-          &HangMonitorParent::DispatchTabChildNotReady, aTabId));
-    }
+    Unused << SendForcePaint(aTabId, aLayerObserverEpoch);
   }
 }
 
@@ -770,14 +725,6 @@ HangMonitorParent::TakeBrowserMinidump(const PluginHangData& aPhd,
   return false;
 }
 
-mozilla::ipc::IPCResult
-HangMonitorParent::RecvReady()
-{
-  MOZ_RELEASE_ASSERT(MessageLoop::current() == MonitorLoop());
-  mReady = true;
-  return IPC_OK();
-}
-
 mozilla::ipc::IPCResult
 HangMonitorParent::RecvHangEvidence(const HangData& aHangData)
 {
@@ -1083,17 +1030,6 @@ HangMonitoredProcess::UserCanceled()
   return NS_OK;
 }
 
-void
-HangMonitoredProcess::DispatchTabChildNotReady(TabId aTabId)
-{
-  MOZ_RELEASE_ASSERT(NS_IsMainThread());
-  if (!mContentParent) {
-    return;
-  }
-
-  Unused << mContentParent->RecvTabChildNotReady(aTabId);
-}
-
 static bool
 InterruptCallback(JSContext* cx)
 {

dom/ipc/TabParent.cpp

@@ -3267,52 +3267,6 @@ TabParent::LiveResizeStopped()
   SuppressDisplayport(false);
 }
 
-void
-TabParent::DispatchTabChildNotReadyEvent()
-{
-  MOZ_ASSERT(NS_IsMainThread());
-
-  nsCOMPtr<mozilla::dom::EventTarget> target = do_QueryInterface(mFrameElement);
-  if (!target) {
-    NS_WARNING("Could not locate target for tab child not ready event.");
-    return;
-  }
-
-  if (mHasPresented) {
-    // We shouldn't dispatch this event because clearly the
-    // TabChild _became_ ready by the time we were told to
-    // dispatch.
-    return;
-  }
-
-  if (!mDocShellIsActive) {
-    return;
-  }
-
-  RefPtr<nsFrameLoader> frameLoader = GetFrameLoader(true);
-  if (!frameLoader) {
-    return;
-  }
-
-  nsCOMPtr<Element> frameElement(mFrameElement);
-  nsCOMPtr<nsIFrameLoaderOwner> owner = do_QueryInterface(frameElement);
-  if (!owner) {
-    return;
-  }
-
-  RefPtr<nsFrameLoader> currentFrameLoader = owner->GetFrameLoader();
-  if (currentFrameLoader != frameLoader) {
-    return;
-  }
-
-  RefPtr<Event> event = NS_NewDOMEvent(mFrameElement, nullptr, nullptr);
-  event->InitEvent(NS_LITERAL_STRING("MozTabChildNotReady"), true, false);
-  event->SetTrusted(true);
-  event->WidgetEventPtr()->mFlags.mOnlyChromeDispatch = true;
-  bool dummy;
-  mFrameElement->DispatchEvent(event, &dummy);
-}
-
 NS_IMETHODIMP
 FakeChannel::OnAuthAvailable(nsISupports *aContext, nsIAuthInformation *aAuthInfo)
 {

dom/ipc/TabParent.h

@@ -587,8 +587,6 @@ public:
   void LiveResizeStarted() override;
   void LiveResizeStopped() override;
 
-  void DispatchTabChildNotReadyEvent();
-
 protected:
   bool ReceiveMessage(const nsString& aMessage,
                       bool aSync,