Bug 1261657 - Don't record SSTabRestored events in StartupPerformance that are the result of a remoteness flip. r=Yoric

MozReview-Commit-ID: 2pnT2DdKPHV

--HG--
extra : rebase_source : f64f2007b7738c259996402a722b3a9bfcab5e0d

browser/components/sessionstore/SessionStore.jsm

@@ -838,7 +838,7 @@ var SessionStoreInternal = {
         SessionStoreInternal._resetLocalTabRestoringState(tab);
         SessionStoreInternal.restoreNextTab();
 
-        this._sendTabRestoredNotification(tab);
+        this._sendTabRestoredNotification(tab, data.isRemotenessUpdate);
         break;
       case "SessionStore:crashedTabRevived":
         // The browser was revived by navigating to a different page
@@ -3286,6 +3286,9 @@ var SessionStoreInternal = {
    *        the tab to restore
    * @param aLoadArguments
    *        optional load arguments used for loadURI()
+   * @param aRemotenessSwitch
+   *        true if we're restoring a tab's content because we flipped
+   *        its remoteness (out-of-process) state.
    */
   restoreTabContent: function (aTab, aLoadArguments = null) {
     if (aTab.hasAttribute("customizemode")) {
@@ -3309,7 +3312,8 @@ var SessionStoreInternal = {
     // flip the remoteness of any browser that is not being displayed.
     this.markTabAsRestoring(aTab);
 
-    if (tabbrowser.updateBrowserRemotenessByURL(browser, uri)) {
+    let isRemotenessUpdate = tabbrowser.updateBrowserRemotenessByURL(browser, uri);
+    if (isRemotenessUpdate) {
       // We updated the remoteness, so we need to send the history down again.
       //
       // Start a new epoch to discard all frame script messages relating to a
@@ -3332,7 +3336,7 @@ var SessionStoreInternal = {
     }
 
     browser.messageManager.sendAsyncMessage("SessionStore:restoreTabContent",
-      {loadArguments: aLoadArguments});
+      {loadArguments: aLoadArguments, isRemotenessUpdate});
   },
 
   /**
@@ -3977,11 +3981,17 @@ var SessionStoreInternal = {
 
   /**
    * Dispatch the SSTabRestored event for the given tab.
-   * @param aTab the which has been restored
+   * @param aTab
+   *        The tab which has been restored
+   * @param aIsRemotenessUpdate
+   *        True if this tab was restored due to flip from running from
+   *        out-of-main-process to in-main-process or vice-versa.
    */
-  _sendTabRestoredNotification: function ssi_sendTabRestoredNotification(aTab) {
-    let event = aTab.ownerDocument.createEvent("Events");
-    event.initEvent("SSTabRestored", true, false);
+  _sendTabRestoredNotification(aTab, aIsRemotenessUpdate) {
+    let event = aTab.ownerDocument.createEvent("CustomEvent");
+    event.initCustomEvent("SSTabRestored", true, false, {
+      isRemotenessUpdate: aIsRemotenessUpdate,
+    });
     aTab.dispatchEvent(event);
   },
 

browser/components/sessionstore/StartupPerformance.jsm

@@ -199,9 +199,16 @@ this.StartupPerformance = {
           // to reach that point.
           let win = subject;
 
-          let observer = () => {
-            this._latestRestoredTimeStamp = Date.now();
-            this._totalNumberOfEagerTabs += 1;
+          let observer = (event) => {
+            // We don't care about tab restorations that are due to
+            // a browser flipping from out-of-main-process to in-main-process
+            // or vice-versa. We only care about restorations that are due
+            // to the user switching to a lazily restored tab, or for tabs
+            // that are restoring eagerly.
+            if (!event.detail.isRemotenessUpdate) {
+              this._latestRestoredTimeStamp = Date.now();
+              this._totalNumberOfEagerTabs += 1;
+            }
           };
           win.gBrowser.tabContainer.addEventListener("SSTabRestored", observer);
           this._totalNumberOfTabs += win.gBrowser.tabContainer.itemCount;

browser/components/sessionstore/content/content-sessionStore.js

@@ -167,21 +167,21 @@ var MessageListener = {
     sendSyncMessage("SessionStore:restoreHistoryComplete", {epoch});
   },
 
-  restoreTabContent({loadArguments}) {
+  restoreTabContent({loadArguments, isRemotenessUpdate}) {
     let epoch = gCurrentEpoch;
 
     // We need to pass the value of didStartLoad back to SessionStore.jsm.
     let didStartLoad = gContentRestore.restoreTabContent(loadArguments, () => {
       // Tell SessionStore.jsm that it may want to restore some more tabs,
       // since it restores a max of MAX_CONCURRENT_TAB_RESTORES at a time.
-      sendAsyncMessage("SessionStore:restoreTabContentComplete", {epoch});
+      sendAsyncMessage("SessionStore:restoreTabContentComplete", {epoch, isRemotenessUpdate});
     });
 
     sendAsyncMessage("SessionStore:restoreTabContentStarted", {epoch});
 
     if (!didStartLoad) {
       // Pretend that the load succeeded so that event handlers fire correctly.
-      sendAsyncMessage("SessionStore:restoreTabContentComplete", {epoch});
+      sendAsyncMessage("SessionStore:restoreTabContentComplete", {epoch, isRemotenessUpdate});
     }
   },