about:startup - record timestamp early on in the XRE setup

toolkit/xre/nsAppData.cpp

@@ -72,6 +72,10 @@ ScopedAppData::ScopedAppData(const nsXREAppData* aAppData)
 
   this->size = aAppData->size;
 
+  if (aAppData->size > offsetof(nsXREAppData, startupTimestamp)) {
+    this->startupTimestamp = PR_IntervalNow();
+  }
+
   SetAllocatedString(this->vendor, aAppData->vendor);
   SetAllocatedString(this->name, aAppData->name);
   SetAllocatedString(this->version, aAppData->version);

toolkit/xre/nsAppRunner.cpp

@@ -805,6 +805,21 @@ nsXULAppInfo::InvalidateCachesOnRestart()
   return NS_OK;
 }
 
+/* readonly attribute unsigned long launchTimestamp; */
+NS_IMETHODIMP nsXULAppInfo::GetLaunchTimestamp(PRUint32 *aTimestamp)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+/* readonly attribute unsigned long startupTimestamp; */
+NS_IMETHODIMP nsXULAppInfo::GetStartupTimestamp(PRUint32 *aTimestamp)
+{
+  *aTimestamp = gAppData->startupTimestamp;
+  return NS_OK;
+}
+
+
+
 #ifdef XP_WIN
 // Matches the enum in WinNT.h for the Vista SDK but renamed so that we can
 // safely build with the Vista SDK and without it.

xpcom/build/nsXULAppAPI.h

@@ -151,6 +151,11 @@ struct nsXREAppData
    *   UAppData = $HOME/$profile
    */
   const char *profile;
+
+  /**
+   * 
+   */
+  PRIntervalTime startupTimestamp;
 };
 
 /**

xpcom/system/nsIXULRuntime.idl

@@ -107,4 +107,7 @@ interface nsIXULRuntime : nsISupports
    * fastload data to be re-created.
    */
   void invalidateCachesOnRestart();
+
+  readonly attribute unsigned long launchTimestamp;
+  readonly attribute unsigned long startupTimestamp;
 };