Bug 1580168 Part 1 - Add processID and isParent accessors to ProcessMessageManager, r=nika.

Differential Revision: https://phabricator.services.mozilla.com/D48084

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

dom/base/ProcessMessageManager.cpp

@@ -17,7 +17,10 @@ ProcessMessageManager::ProcessMessageManager(
     ParentProcessMessageManager* aParentManager, MessageManagerFlags aFlags)
     : MessageSender(aCallback, aParentManager,
                     aFlags | MessageManagerFlags::MM_CHROME |
-                        MessageManagerFlags::MM_PROCESSMANAGER) {
+                        MessageManagerFlags::MM_PROCESSMANAGER),
+      mPid(-1),
+      // aCallback is only specified if this is the in-process manager.
+      mInProcess(!!aCallback) {
   MOZ_ASSERT(!(aFlags & ~(MessageManagerFlags::MM_GLOBAL |
                           MessageManagerFlags::MM_OWNSCALLBACK)));
 

dom/base/ProcessMessageManager.h

@@ -41,6 +41,15 @@ class ProcessMessageManager final : public MessageSender {
                                 mozilla::ErrorResult& aError) {
     GetDelayedScripts(aCx, aScripts, aError);
   }
+
+  void SetOsPid(int32_t aPid) { mPid = aPid; }
+  int32_t OsPid() const { return mPid; }
+
+  bool IsInProcess() const { return mInProcess; }
+
+ private:
+  int32_t mPid;
+  bool mInProcess;
 };
 
 }  // namespace dom

dom/base/nsFrameMessageManager.cpp

@@ -1592,6 +1592,7 @@ ProcessMessageManager* nsFrameMessageManager::NewProcessMessageManager(
         new ProcessMessageManager(new SameParentProcessMessageManagerCallback(),
                                   nsFrameMessageManager::sParentProcessManager,
                                   MessageManagerFlags::MM_OWNSCALLBACK);
+    mm->SetOsPid(base::GetCurrentProcId());
     sSameProcessParentManager = mm;
   }
   return mm;

dom/chrome-webidl/MessageManager.webidl

@@ -611,5 +611,10 @@ ChromeMessageSender includes FrameScriptLoader;
 [ChromeOnly, Exposed=Window]
 interface ProcessMessageManager : MessageSender
 {
+  // PID of the process being communicated with.
+  readonly attribute long osPid;
+
+  // Whether this is message manager for the current process.
+  readonly attribute boolean isInProcess;
 };
 ProcessMessageManager includes ProcessScriptLoader;

dom/ipc/ContentParent.cpp

@@ -1514,6 +1514,7 @@ void ContentParent::ShutDownMessageManager() {
       mMessageManager, nullptr, CHILD_PROCESS_SHUTDOWN_MESSAGE, false, nullptr,
       nullptr, nullptr, nullptr, IgnoreErrors());
 
+  mMessageManager->SetOsPid(-1);
   mMessageManager->Disconnect();
   mMessageManager = nullptr;
 }
@@ -2556,6 +2557,7 @@ bool ContentParent::InitInternal(ProcessPriority aInitialPriority) {
   // Initialize the message manager (and load delayed scripts) now that we
   // have established communications with the child.
   mMessageManager->InitWithCallback(this);
+  mMessageManager->SetOsPid(Pid());
 
   // Set the subprocess's priority.  We do this early on because we're likely
   // /lowering/ the process's CPU and memory priority, which it has inherited