diff -r 000000000000 -r 6474c204b198 layout/printing/nsPagePrintTimer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/printing/nsPagePrintTimer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,180 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsPagePrintTimer.h"
+#include "nsIContentViewer.h"
+#include "nsIServiceManager.h"
+#include "nsPrintEngine.h"
+
+NS_IMPL_ISUPPORTS_INHERITED(nsPagePrintTimer, nsRunnable, nsITimerCallback)
+
+nsPagePrintTimer::~nsPagePrintTimer()
+{
+  // "Destroy" the document viewer; this normally doesn't actually
+  // destroy it because of the IncrementDestroyRefCount call below
+  // XXX This is messy; the document viewer should use a single approach
+  // to keep itself alive during printing
+  nsCOMPtr<nsIContentViewer> cv(do_QueryInterface(mDocViewerPrint));
+  if (cv) {
+    cv->Destroy();
+  }
+}
+
+nsresult 
+nsPagePrintTimer::StartTimer(bool aUseDelay)
+{
+  nsresult result;
+  mTimer = do_CreateInstance("@mozilla.org/timer;1", &result);
+  if (NS_FAILED(result)) {
+    NS_WARNING("unable to start the timer");
+  } else {
+    uint32_t delay = 0;
+    if (aUseDelay) {
+      if (mFiringCount < 10) {
+        // Longer delay for the few first pages.
+        delay = mDelay + ((10 - mFiringCount) * 100);
+      } else {
+        delay = mDelay;
+      }
+    }
+    mTimer->InitWithCallback(this, delay, nsITimer::TYPE_ONE_SHOT);
+  }
+  return result;
+}
+
+nsresult
+nsPagePrintTimer::StartWatchDogTimer()
+{
+  nsresult result;
+  if (mWatchDogTimer) {
+    mWatchDogTimer->Cancel();
+  }
+  mWatchDogTimer = do_CreateInstance("@mozilla.org/timer;1", &result);
+  if (NS_FAILED(result)) {
+    NS_WARNING("unable to start the timer");
+  } else {
+    // Instead of just doing one timer for a long period do multiple so we
+    // can check if the user cancelled the printing.
+    mWatchDogTimer->InitWithCallback(this, WATCH_DOG_INTERVAL,
+                                     nsITimer::TYPE_ONE_SHOT);
+  }
+  return result;
+}
+
+void
+nsPagePrintTimer::StopWatchDogTimer()
+{
+  if (mWatchDogTimer) {
+    mWatchDogTimer->Cancel();
+    mWatchDogTimer = nullptr;
+  }
+}
+
+//nsRunnable
+NS_IMETHODIMP
+nsPagePrintTimer::Run() 
+{
+  bool initNewTimer = true;
+  // Check to see if we are done
+  // inRange will be true if a page is actually printed
+  bool inRange;
+  bool donePrinting;
+
+  // donePrinting will be true if it completed successfully or
+  // if the printing was cancelled
+  donePrinting = mPrintEngine->PrintPage(mPrintObj, inRange);
+  if (donePrinting) {
+    // now clean up print or print the next webshell
+    if (mPrintEngine->DonePrintingPages(mPrintObj, NS_OK)) {
+      initNewTimer = false;
+      mDone = true;
+    }
+  }
+
+  // Note that the Stop() destroys this after the print job finishes
+  // (The PrintEngine stops holding a reference when DonePrintingPages
+  // returns true.)
+  Stop(); 
+  if (initNewTimer) {
+    ++mFiringCount;
+    nsresult result = StartTimer(inRange);
+    if (NS_FAILED(result)) {
+      mDone = true;     // had a failure.. we are finished..
+      mPrintEngine->SetIsPrinting(false);
+    }
+  }
+  return NS_OK;
+}
+
+// nsITimerCallback
+NS_IMETHODIMP
+nsPagePrintTimer::Notify(nsITimer *timer)
+{
+  // When finished there may be still pending notifications, which we can just
+  // ignore.
+  if (mDone) {
+    return NS_OK;
+  }
+
+  // There are three things that call Notify with different values for timer:
+  // 1) the delay between pages (timer == mTimer)
+  // 2) canvasPrintState done (timer == null)
+  // 3) the watch dog timer (timer == mWatchDogTimer)
+  if (timer && timer == mWatchDogTimer) {
+    mWatchDogCount++;
+    if (mWatchDogCount > WATCH_DOG_MAX_COUNT) {
+      Fail();
+      return NS_OK;
+    }
+  } else if(!timer) {
+    // Reset the counter since a mozPrintCallback has finished.
+    mWatchDogCount = 0;
+  }
+
+  if (mDocViewerPrint) {
+    bool donePrePrint = mPrintEngine->PrePrintPage();
+
+    if (donePrePrint) {
+      StopWatchDogTimer();
+      NS_DispatchToMainThread(this);
+    } else {
+      // Start the watch dog if we're waiting for preprint to ensure that if any
+      // mozPrintCallbacks take to long we error out.
+      StartWatchDogTimer();
+    }
+
+  }
+  return NS_OK;
+}
+
+nsresult 
+nsPagePrintTimer::Start(nsPrintObject* aPO)
+{
+  mPrintObj = aPO;
+  mWatchDogCount = 0;
+  mDone = false;
+  return StartTimer(false);
+}
+
+
+void  
+nsPagePrintTimer::Stop()
+{
+  if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nullptr;
+  }
+  StopWatchDogTimer();
+}
+
+void
+nsPagePrintTimer::Fail()
+{
+  mDone = true;
+  Stop();
+  if (mPrintEngine) {
+    mPrintEngine->CleanupOnFailure(NS_OK, false);
+  }
+}