Bug 1696158 - Move CanSavePresentation to the parent process. Make nsDocShell listen for background requests too. r=smaug,necko-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D112201

docshell/base/nsDocShell.cpp

@@ -367,7 +367,7 @@ static bool IsUrgentStart(BrowsingContext* aBrowsingContext,
 
 nsDocShell::nsDocShell(BrowsingContext* aBrowsingContext,
                        uint64_t aContentWindowID)
-    : nsDocLoader(),
+    : nsDocLoader(true),
       mContentWindowID(aContentWindowID),
       mBrowsingContext(aBrowsingContext),
       mForcedCharset(nullptr),

docshell/test/navigation/test_blockBFCache.html

@@ -36,6 +36,17 @@ const blockBFCacheTests = [
       });
     },
   },
+  {
+    name: "Background request",
+    test: () => {
+      return new Promise((resolve) => {
+        const xhr = new XMLHttpRequest();
+        xhr.open("GET", "slow.sjs");
+        xhr.addEventListener("readystatechange", () => { if (xhr.readyState == xhr.HEADERS_RECEIVED) resolve(xhr); });
+        xhr.send();
+      });
+    },
+  },
   {
     name: "getUserMedia",
     prefs: getUserMediaPrefs,

netwerk/base/nsLoadGroup.cpp

@@ -465,10 +465,13 @@ nsLoadGroup::AddRequest(nsIRequest* request, nsISupports* ctxt) {
   nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(request);
   if (timedChannel) timedChannel->SetTimingEnabled(true);
 
-  if (!(flags & nsIRequest::LOAD_BACKGROUND)) {
+  bool foreground = !(flags & nsIRequest::LOAD_BACKGROUND);
+  if (foreground) {
     // Update the count of foreground URIs..
     mForegroundCount += 1;
+  }
 
+  if (foreground || mNotifyObserverAboutBackgroundRequests) {
     //
     // Fire the OnStartRequest notification out to the observer...
     //
@@ -495,12 +498,14 @@ nsLoadGroup::AddRequest(nsIRequest* request, nsISupports* ctxt) {
 
         rv = NS_OK;
 
-        mForegroundCount -= 1;
+        if (foreground) {
+          mForegroundCount -= 1;
+        }
       }
     }
 
     // Ensure that we're part of our loadgroup while pending
-    if (mForegroundCount == 1 && mLoadGroup) {
+    if (foreground && mForegroundCount == 1 && mLoadGroup) {
       mLoadGroup->AddRequest(this, nullptr);
     }
   }
@@ -601,10 +606,13 @@ nsresult nsLoadGroup::NotifyRemovalObservers(nsIRequest* request,
   nsresult rv = request->GetLoadFlags(&flags);
   if (NS_FAILED(rv)) return rv;
 
-  if (!(flags & nsIRequest::LOAD_BACKGROUND)) {
+  bool foreground = !(flags & nsIRequest::LOAD_BACKGROUND);
+  if (foreground) {
     NS_ASSERTION(mForegroundCount > 0, "ForegroundCount messed up");
     mForegroundCount -= 1;
+  }
 
+  if (foreground || mNotifyObserverAboutBackgroundRequests) {
     // Fire the OnStopRequest out to the observer...
     nsCOMPtr<nsIRequestObserver> observer = do_QueryReferent(mObserver);
     if (observer) {
@@ -622,7 +630,7 @@ nsresult nsLoadGroup::NotifyRemovalObservers(nsIRequest* request,
     }
 
     // If that was the last request -> remove ourselves from loadgroup
-    if (mForegroundCount == 0 && mLoadGroup) {
+    if (foreground && mForegroundCount == 0 && mLoadGroup) {
       mLoadGroup->RemoveRequest(this, nullptr, aStatus);
     }
   }
@@ -645,10 +653,16 @@ nsLoadGroup::GetRequests(nsISimpleEnumerator** aRequests) {
 
 NS_IMETHODIMP
 nsLoadGroup::SetGroupObserver(nsIRequestObserver* aObserver) {
-  mObserver = do_GetWeakReference(aObserver);
+  SetGroupObserver(aObserver, false);
   return NS_OK;
 }
 
+void nsLoadGroup::SetGroupObserver(nsIRequestObserver* aObserver,
+                                   bool aIncludeBackgroundRequests) {
+  mObserver = do_GetWeakReference(aObserver);
+  mNotifyObserverAboutBackgroundRequests = aIncludeBackgroundRequests;
+}
+
 NS_IMETHODIMP
 nsLoadGroup::GetGroupObserver(nsIRequestObserver** aResult) {
   nsCOMPtr<nsIRequestObserver> observer = do_QueryReferent(mObserver);

netwerk/base/nsLoadGroup.h

@@ -58,6 +58,9 @@ class nsLoadGroup : public nsILoadGroup,
   nsresult Init();
   nsresult InitWithRequestContextId(const uint64_t& aRequestContextId);
 
+  void SetGroupObserver(nsIRequestObserver* aObserver,
+                        bool aIncludeBackgroundRequests);
+
  protected:
   virtual ~nsLoadGroup();
 
@@ -94,6 +97,7 @@ class nsLoadGroup : public nsILoadGroup,
   bool mDefaultLoadIsTimed;
   bool mBrowsingContextDiscarded;
   bool mExternalRequestContext;
+  bool mNotifyObserverAboutBackgroundRequests;
 
   /* Telemetry */
   mozilla::TimeStamp mDefaultRequestCreationTime;

uriloader/base/nsDocLoader.cpp

@@ -103,7 +103,7 @@ class nsDefaultComparator<nsDocLoader::nsListenerInfo,
     PLDHashTable::MoveEntryStub, nsDocLoader::RequestInfoHashClearEntry,
     nsDocLoader::RequestInfoHashInitEntry};
 
-nsDocLoader::nsDocLoader()
+nsDocLoader::nsDocLoader(bool aNotifyAboutBackgroundRequests)
     : mParent(nullptr),
       mProgressStateFlags(0),
       mCurrentSelfProgress(0),
@@ -119,7 +119,8 @@ nsDocLoader::nsDocLoader()
       mTreatAsBackgroundLoad(false),
       mHasFakeOnLoadDispatched(false),
       mIsReadyToHandlePostMessage(false),
-      mDocumentOpenedButNotLoaded(false) {
+      mDocumentOpenedButNotLoaded(false),
+      mNotifyAboutBackgroundRequests(aNotifyAboutBackgroundRequests) {
   ClearInternalProgress();
 
   MOZ_LOG(gDocLoaderLog, LogLevel::Debug, ("DocLoader:%p: created.\n", this));
@@ -131,9 +132,14 @@ nsresult nsDocLoader::SetDocLoaderParent(nsDocLoader* aParent) {
 }
 
 nsresult nsDocLoader::Init() {
-  nsresult rv = NS_NewLoadGroup(getter_AddRefs(mLoadGroup), this);
+  RefPtr<net::nsLoadGroup> loadGroup = new net::nsLoadGroup();
+  nsresult rv = loadGroup->Init();
   if (NS_FAILED(rv)) return rv;
 
+  loadGroup->SetGroupObserver(this, mNotifyAboutBackgroundRequests);
+
+  mLoadGroup = loadGroup;
+
   MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
           ("DocLoader:%p: load group %p.\n", this, mLoadGroup.get()));
 
@@ -150,8 +156,7 @@ nsresult nsDocLoader::InitWithBrowsingContext(
       aBrowsingContext->GetRequestContextId());
   if (NS_FAILED(rv)) return rv;
 
-  rv = loadGroup->SetGroupObserver(this);
-  if (NS_FAILED(rv)) return rv;
+  loadGroup->SetGroupObserver(this, mNotifyAboutBackgroundRequests);
 
   mLoadGroup = loadGroup;
 
@@ -404,6 +409,14 @@ NS_IMETHODIMP
 nsDocLoader::OnStartRequest(nsIRequest* request) {
   // called each time a request is added to the group.
 
+  // Some docloaders deal with background requests in their OnStartRequest
+  // override, but here we don't want to do anything with them, so return early.
+  nsLoadFlags loadFlags = 0;
+  request->GetLoadFlags(&loadFlags);
+  if (loadFlags & nsIRequest::LOAD_BACKGROUND) {
+    return NS_OK;
+  }
+
   if (MOZ_LOG_TEST(gDocLoaderLog, LogLevel::Debug)) {
     nsAutoCString name;
     request->GetName(name);
@@ -420,9 +433,6 @@ nsDocLoader::OnStartRequest(nsIRequest* request) {
 
   bool justStartedLoading = false;
 
-  nsLoadFlags loadFlags = 0;
-  request->GetLoadFlags(&loadFlags);
-
   if (!mIsLoadingDocument && (loadFlags & nsIChannel::LOAD_DOCUMENT_URI)) {
     justStartedLoading = true;
     mIsLoadingDocument = true;
@@ -496,6 +506,14 @@ nsDocLoader::OnStartRequest(nsIRequest* request) {
 
 NS_IMETHODIMP
 nsDocLoader::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  // Some docloaders deal with background requests in their OnStopRequest
+  // override, but here we don't want to do anything with them, so return early.
+  nsLoadFlags lf = 0;
+  aRequest->GetLoadFlags(&lf);
+  if (lf & nsIRequest::LOAD_BACKGROUND) {
+    return NS_OK;
+  }
+
   nsresult rv = NS_OK;
 
   if (MOZ_LOG_TEST(gDocLoaderLog, LogLevel::Debug)) {
@@ -575,8 +593,6 @@ nsDocLoader::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
           //
           // Only if the load has been targeted (see bug 268483)...
           //
-          uint32_t lf;
-          channel->GetLoadFlags(&lf);
           if (lf & nsIChannel::LOAD_TARGETED) {
             nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aRequest));
             if (httpChannel) {

uriloader/base/nsDocLoader.h

@@ -59,7 +59,7 @@ class nsDocLoader : public nsIDocumentLoader,
 
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_THIS_DOCLOADER_IMPL_CID)
 
-  nsDocLoader();
+  nsDocLoader() : nsDocLoader(false) {}
 
   [[nodiscard]] virtual nsresult Init();
   [[nodiscard]] nsresult InitWithBrowsingContext(
@@ -159,6 +159,7 @@ class nsDocLoader : public nsIDocumentLoader,
   uint32_t ChildCount() const { return mChildList.Length(); }
 
  protected:
+  explicit nsDocLoader(bool aNotifyAboutBackgroundRequests);
   virtual ~nsDocLoader();
 
   [[nodiscard]] virtual nsresult SetDocLoaderParent(nsDocLoader* aLoader);
@@ -363,6 +364,8 @@ class nsDocLoader : public nsIDocumentLoader,
    */
   bool mDocumentOpenedButNotLoaded;
 
+  bool mNotifyAboutBackgroundRequests;
+
   static const PLDHashTableOps sRequestInfoHashOps;
 
   // A list of kids that are in the middle of their onload calls and will let