Bug 1174666 - Remove unneeded SessionSaver.clearLastSaveTime() r=Yoric

browser/components/sessionstore/SessionSaver.jsm

@@ -91,14 +91,6 @@ this.SessionSaver = Object.freeze({
     SessionSaverInternal.updateLastSaveTime();
   },
 
-  /**
-   * Sets the last save time to zero. This will cause us to
-   * immediately save the next time runDelayed() is called.
-   */
-  clearLastSaveTime: function () {
-    SessionSaverInternal.clearLastSaveTime();
-  },
-
   /**
    * Cancels all pending session saves.
    */
@@ -161,14 +153,6 @@ let SessionSaverInternal = {
     this._lastSaveTime = Date.now();
   },
 
-  /**
-   * Sets the last save time to zero. This will cause us to
-   * immediately save the next time runDelayed() is called.
-   */
-  clearLastSaveTime: function () {
-    this._lastSaveTime = 0;
-  },
-
   /**
    * Cancels all pending session saves.
    */

browser/components/sessionstore/SessionStore.jsm

@@ -909,10 +909,13 @@ let SessionStoreInternal = {
     // perform additional initialization when the first window is loading
     if (RunState.isStopped) {
       RunState.setRunning();
-      SessionSaver.updateLastSaveTime();
 
       // restore a crashed session resp. resume the last session if requested
       if (aInitialState) {
+        // Don't write to disk right after startup. Set the last time we wrote
+        // to disk to NOW() to enforce a full interval before the next write.
+        SessionSaver.updateLastSaveTime();
+
         if (isPrivateWindow) {
           // We're starting with a single private window. Save the state we
           // actually wanted to restore so that we can do it later in case
@@ -937,9 +940,6 @@ let SessionStoreInternal = {
       else {
         // Nothing to restore, notify observers things are complete.
         Services.obs.notifyObservers(null, NOTIFY_WINDOWS_RESTORED, "");
-
-        // The next delayed save request should execute immediately.
-        SessionSaver.clearLastSaveTime();
       }
     }
     // this window was opened by _openWindowWithState