15 files changed, 314 insertions, 62 deletions

diff --git a/chrome/browser/printing/print_preview_message_handler.cc b/chrome/browser/printing/print_preview_message_handler.cc
index 99714cf..c91a143 100644
--- a/chrome/browser/printing/print_preview_message_handler.cc
+++ b/chrome/browser/printing/print_preview_message_handler.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/printing/print_preview_message_handler.h"
 
+#include <vector>
+
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/printing/background_printing_manager.h"
@@ -61,6 +63,35 @@ void PrintPreviewMessageHandler::OnRequestPrintPreview() {
   PrintPreviewTabController::PrintPreview(tab_contents());
 }
 
+void PrintPreviewMessageHandler::OnDidGetPreviewPageCount(int page_count) {
+  if (page_count <= 0)
+    return;
+  TabContents* print_preview_tab = GetPrintPreviewTab();
+  if (!print_preview_tab)
+    return;
+
+  PrintPreviewUI* print_preview_ui =
+      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
+  print_preview_ui->OnDidGetPreviewPageCount(page_count);
+}
+
+void PrintPreviewMessageHandler::OnDidPreviewPage(int page_number,
+                                                  bool* cancel) {
+  TabContents* print_preview_tab = GetPrintPreviewTab();
+  if (!print_preview_tab) {
+    // Can't find print preview tab means we should cancel.
+    *cancel = true;
+    return;
+  }
+
+  PrintPreviewUI* print_preview_ui =
+      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
+  bool has_pending = print_preview_ui->HasPendingRequests();
+  if (!has_pending && page_number >= 0)
+    print_preview_ui->OnDidPreviewPage(page_number);
+  *cancel = has_pending;
+}
+
 void PrintPreviewMessageHandler::OnPagesReadyForPreview(
     const PrintHostMsg_DidPreviewDocument_Params& params) {
   // Always need to stop the worker and send PrintMsg_PrintingDone.
@@ -135,20 +166,39 @@ void PrintPreviewMessageHandler::OnPrintPreviewFailed(int document_cookie) {
   } else {
     PrintPreviewUI* print_preview_ui =
       static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
-    print_preview_ui->CallJavascriptFunction("printPreviewFailed");
+    print_preview_ui->OnPrintPreviewFailed();
   }
 }
 
+void PrintPreviewMessageHandler::OnPrintPreviewCancelled(int document_cookie) {
+  // Always need to stop the worker.
+  StopWorker(document_cookie);
+
+  TabContents* print_preview_tab = GetPrintPreviewTab();
+  if (!print_preview_tab)
+    return;
+
+  PrintPreviewUI* print_preview_ui =
+      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
+  print_preview_ui->OnPrintPreviewCancelled();
+}
+
 bool PrintPreviewMessageHandler::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintPreviewMessageHandler, message)
     IPC_MESSAGE_HANDLER(PrintHostMsg_RequestPrintPreview,
                         OnRequestPrintPreview)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPreviewPageCount,
+                        OnDidGetPreviewPageCount)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_DidPreviewPage,
+                        OnDidPreviewPage)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PagesReadyForPreview,
                         OnPagesReadyForPreview)
     IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewFailed,
                         OnPrintPreviewFailed)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_PrintPreviewCancelled,
+                        OnPrintPreviewCancelled)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
diff --git a/chrome/browser/printing/print_preview_message_handler.h b/chrome/browser/printing/print_preview_message_handler.h
index 6591bc7..1421de9 100644
--- a/chrome/browser/printing/print_preview_message_handler.h
+++ b/chrome/browser/printing/print_preview_message_handler.h
@@ -30,9 +30,13 @@ class PrintPreviewMessageHandler : public TabContentsObserver {
 
   // Message handlers.
   void OnRequestPrintPreview();
+  void OnDidGetPreviewPageCount(int page_count);
+  // |page_number| is 0-based.
+  void OnDidPreviewPage(int page_number, bool* cancel);
   void OnPagesReadyForPreview(
       const PrintHostMsg_DidPreviewDocument_Params& params);
   void OnPrintPreviewFailed(int document_cookie);
+  void OnPrintPreviewCancelled(int document_cookie);
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewMessageHandler);
 };
diff --git a/chrome/browser/resources/print_preview/print_preview.js b/chrome/browser/resources/print_preview/print_preview.js
index 66bdcb3..1e57797 100644
--- a/chrome/browser/resources/print_preview/print_preview.js
+++ b/chrome/browser/resources/print_preview/print_preview.js
@@ -599,57 +599,87 @@ function onPDFLoad() {
 }
 
 /**
+ * Update the page count and check the page range.
+ * Called from PrintPreviewUI::OnDidGetPreviewPageCount().
+ * @param {number} pageCount The number of pages.
+ */
+function onDidGetPreviewPageCount(pageCount) {
+  totalPageCount = pageCount;
+
+  if (!isSelectedPagesValid())
+    pageRangesFieldChanged();
+}
+
+/**
+ * Notification that a print preview page has been rendered.
+ * Check if the settings have changed and request a regeneration if needed.
+ * Called from PrintPreviewUI::OnDidPreviewPage().
+ * @param {number} pageNumber The page number, 0-based.
+ */
+function onDidPreviewPage(pageNumber) {
+  if (checkIfSettingsChangedAndRegeneratePreview())
+    return;
+  // TODO(thestig) Make use of |pageNumber| for pipelined preview generation.
+}
+
+/**
  * Update the print preview when new preview data is available.
  * Create the PDF plugin as needed.
  * Called from PrintPreviewUI::PreviewDataIsAvailable().
- * @param {number} pageCount The expected total pages count.
  * @param {string} jobTitle The print job title.
  * @param {boolean} modifiable If the preview is modifiable.
  * @param {string} previewUid Preview unique identifier.
  */
-function updatePrintPreview(pageCount, jobTitle, modifiable, previewUid) {
-  var tempPrintSettings = new PrintSettings();
-  tempPrintSettings.save();
+function updatePrintPreview(jobTitle, modifiable, previewUid) {
+  hasPendingPreviewRequest = false;
+
+  if (checkIfSettingsChangedAndRegeneratePreview())
+    return;
 
   previewModifiable = modifiable;
+  document.title = localStrings.getStringF('printPreviewTitleFormat', jobTitle);
 
-  hasPendingPreviewRequest = false;
+  createPDFPlugin(previewUid);
+  updatePrintSummary();
+  updatePrintButtonState();
+  addEventListeners();
 
-  if (!totalPageCount)
-    totalPageCount = pageCount;
+  if (hasPendingPrintFileRequest)
+    printPendingFile();
+}
+
+/**
+ * Check if any print settings changed and regenerate the preview if needed.
+ * @return {boolean} true if a new preview is required.
+ */
+function checkIfSettingsChangedAndRegeneratePreview() {
+  var tempPrintSettings = new PrintSettings();
+  tempPrintSettings.save();
 
-  if (previouslySelectedPages.length == 0)
-    for (var i = 0; i < totalPageCount; i++)
+  if (previouslySelectedPages.length == 0) {
+    for (var i = 0; i < totalPageCount; i++) {
       previouslySelectedPages.push(i+1);
+    }
+  }
 
   if (printSettings.deviceName != tempPrintSettings.deviceName) {
     updateControlsWithSelectedPrinterCapabilities();
-    return;
+    return true;
   } else if (printSettings.isLandscape != tempPrintSettings.isLandscape) {
     setDefaultValuesAndRegeneratePreview();
-    return;
+    return true;
   } else if (isSelectedPagesValid()) {
     var currentlySelectedPages = getSelectedPagesSet();
     if (!areArraysEqual(previouslySelectedPages, currentlySelectedPages)) {
       previouslySelectedPages = currentlySelectedPages;
       requestPrintPreview();
-      return;
+      return true;
     }
   }
 
   if (!isSelectedPagesValid())
     pageRangesFieldChanged();
-
-  // Update the current tab title.
-  document.title = localStrings.getStringF('printPreviewTitleFormat', jobTitle);
-
-  createPDFPlugin(previewUid);
-  updatePrintSummary();
-  updatePrintButtonState();
-  addEventListeners();
-
-  if (hasPendingPrintFileRequest)
-    printPendingFile();
+  return false;
 }
 
 /**
diff --git a/chrome/browser/ui/webui/print_preview_handler.cc b/chrome/browser/ui/webui/print_preview_handler.cc
index 8a141e6..55ffe15 100644
--- a/chrome/browser/ui/webui/print_preview_handler.cc
+++ b/chrome/browser/ui/webui/print_preview_handler.cc
@@ -430,22 +430,25 @@ void PrintPreviewHandler::HandleGetPrinters(const ListValue*) {
 }
 
 void PrintPreviewHandler::HandleGetPreview(const ListValue* args) {
+  scoped_ptr<DictionaryValue> settings(GetSettingsDictionary(args));
+  if (!settings.get())
+    return;
+
   // Increment request count.
   ++regenerate_preview_request_count_;
 
+  PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(web_ui_);
+  print_preview_ui->OnPrintPreviewRequest();
+
   TabContents* initiator_tab = GetInitiatorTab();
   if (!initiator_tab) {
     if (!reported_failed_preview_) {
       ReportUserActionHistogram(PREVIEW_FAILED);
       reported_failed_preview_ = true;
     }
-    web_ui_->CallJavascriptFunction("printPreviewFailed");
+    print_preview_ui->OnPrintPreviewFailed();
     return;
   }
-  scoped_ptr<DictionaryValue> settings(GetSettingsDictionary(args));
-  if (!settings.get())
-    return;
-
   VLOG(1) << "Print preview request start";
   RenderViewHost* rvh = initiator_tab->render_view_host();
   rvh->Send(new PrintMsg_PrintPreview(rvh->routing_id(), *settings));
diff --git a/chrome/browser/ui/webui/print_preview_ui.cc b/chrome/browser/ui/webui/print_preview_ui.cc
index 339a506..e5efdfa 100644
--- a/chrome/browser/ui/webui/print_preview_ui.cc
+++ b/chrome/browser/ui/webui/print_preview_ui.cc
@@ -15,7 +15,8 @@
 
 PrintPreviewUI::PrintPreviewUI(TabContents* contents)
     : ChromeWebUI(contents),
-      initial_preview_start_time_(base::TimeTicks::Now()) {
+      initial_preview_start_time_(base::TimeTicks::Now()),
+      request_count_(0U) {
   // WebUI owns |handler_|.
   handler_ = new PrintPreviewHandler();
   AddMessageHandler(handler_->Attach(this));
@@ -49,11 +50,29 @@ void PrintPreviewUI::OnInitiatorTabClosed(
   CallJavascriptFunction("onInitiatorTabClosed", initiator_tab_url);
 }
 
+void PrintPreviewUI::OnPrintPreviewRequest() {
+  request_count_++;
+}
+
+void PrintPreviewUI::OnDidGetPreviewPageCount(int page_count) {
+  DCHECK_GT(page_count, 0);
+  FundamentalValue count(page_count);
+  CallJavascriptFunction("onDidGetPreviewPageCount", count);
+}
+
+void PrintPreviewUI::OnDidPreviewPage(int page_number) {
+  DCHECK_GE(page_number, 0);
+  FundamentalValue number(page_number);
+  CallJavascriptFunction("onDidPreviewPage", number);
+}
+
 void PrintPreviewUI::OnPreviewDataIsAvailable(int expected_pages_count,
                                               const string16& job_title,
                                               bool modifiable) {
   VLOG(1) << "Print preview request finished with "
           << expected_pages_count << " pages";
+  DecrementRequestCount();
+
   if (!initial_preview_start_time_.is_null()) {
     UMA_HISTOGRAM_TIMES("PrintPreview.InitalDisplayTime",
                         base::TimeTicks::Now() - initial_preview_start_time_);
@@ -65,8 +84,8 @@ void PrintPreviewUI::OnPreviewDataIsAvailable(int expected_pages_count,
   StringValue title(job_title);
   FundamentalValue is_preview_modifiable(modifiable);
   StringValue ui_identifier(preview_ui_addr_str_);
-  CallJavascriptFunction("updatePrintPreview", pages_count, title,
-                         is_preview_modifiable, ui_identifier);
+  CallJavascriptFunction("updatePrintPreview", title, is_preview_modifiable,
+                         ui_identifier);
 }
 
 void PrintPreviewUI::OnNavigation() {
@@ -77,6 +96,25 @@ void PrintPreviewUI::OnFileSelectionCancelled() {
   CallJavascriptFunction("fileSelectionCancelled");
 }
 
+void PrintPreviewUI::OnPrintPreviewFailed() {
+  DecrementRequestCount();
+  CallJavascriptFunction("printPreviewFailed");
+}
+
+void PrintPreviewUI::OnPrintPreviewCancelled() {
+  DecrementRequestCount();
+}
+
+bool PrintPreviewUI::HasPendingRequests() {
+  return request_count_ > 1;
+}
+
 PrintPreviewDataService* PrintPreviewUI::print_preview_data_service() {
   return PrintPreviewDataService::GetInstance();
 }
+
+void PrintPreviewUI::DecrementRequestCount() {
+  DCHECK_GT(request_count_, 0U);
+  if (request_count_ > 0)
+    request_count_--;
+}
diff --git a/chrome/browser/ui/webui/print_preview_ui.h b/chrome/browser/ui/webui/print_preview_ui.h
index 7637801..f2d44ce 100644
--- a/chrome/browser/ui/webui/print_preview_ui.h
+++ b/chrome/browser/ui/webui/print_preview_ui.h
@@ -30,6 +30,17 @@ class PrintPreviewUI : public ChromeWebUI {
   // Sets the print preview |data|.
   void SetPrintPreviewData(const RefCountedBytes* data);
 
+  // Notify the Web UI that there is a print preview request.
+  // There should be a matching call to OnPreviewDataIsAvailable() or
+  // OnPrintPreviewFailed().
+  void OnPrintPreviewRequest();
+
+  // Notify the Web UI that the print preview will have |page_count| pages.
+  void OnDidGetPreviewPageCount(int page_count);
+
+  // Notify the Web UI that the 0-based page |page_number| has been rendered.
+  void OnDidPreviewPage(int page_number);
+
   // Notify the Web UI renderer that preview data is available.
   // |expected_pages_count| specifies the total number of pages.
   // |job_title| is the title of the page being previewed.
@@ -44,6 +55,12 @@ class PrintPreviewUI : public ChromeWebUI {
   // erased.
   void OnNavigation();
 
+  // Notify the Web UI that the print preview failed to render.
+  void OnPrintPreviewFailed();
+
+  // Notify the Web UI that the print preview request has been cancelled.
+  void OnPrintPreviewCancelled();
+
   // Notify the Web UI that initiator tab is closed, so we can disable all
   // the controls that need the initiator tab for generating the preview data.
   // |initiator_tab_url| is passed in order to display a more accurate error
@@ -53,10 +70,15 @@ class PrintPreviewUI : public ChromeWebUI {
   // Notify the Web UI renderer that file selection has been cancelled.
   void OnFileSelectionCancelled();
 
+  // Return true if there are pending requests.
+  bool HasPendingRequests();
+
  private:
   // Helper function
   PrintPreviewDataService* print_preview_data_service();
 
+  void DecrementRequestCount();
+
   base::TimeTicks initial_preview_start_time_;
 
   // Store the PrintPreviewUI address string.
@@ -65,6 +87,9 @@ class PrintPreviewUI : public ChromeWebUI {
   // Weak pointer to the WebUI handler.
   PrintPreviewHandler* handler_;
 
+  // The number of print preview requests in flight.
+  uint32 request_count_;
+
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewUI);
 };
 
diff --git a/chrome/common/print_messages.h b/chrome/common/print_messages.h
index ec825a5..0c8c48a 100644
--- a/chrome/common/print_messages.h
+++ b/chrome/common/print_messages.h
@@ -228,6 +228,17 @@ IPC_MESSAGE_CONTROL1(PrintHostMsg_TempFileForPrintingWritten,
 // Asks the browser to do print preview.
 IPC_MESSAGE_ROUTED0(PrintHostMsg_RequestPrintPreview)
 
+// Notify the browser the number of pages in the print preview document.
+IPC_MESSAGE_ROUTED1(PrintHostMsg_DidGetPreviewPageCount,
+                    int  /* page count */)
+
+// Notify the browser a print preview page has been rendered. Give the browser
+// a chance to cancel the print preview as needed. Page number is zero-based,
+// and can be -1 if it is just a check.
+IPC_SYNC_MESSAGE_ROUTED1_1(PrintHostMsg_DidPreviewPage,
+                           int  /* page number */,
+                           bool /* print preview cancelled */)
+
 // Sends back to the browser the rendered "printed document" for preview that
 // was requested by a PrintMsg_PrintPreview message. The memory handle in this
 // message is already valid in the browser process.
@@ -241,3 +252,7 @@ IPC_MESSAGE_ROUTED1(PrintHostMsg_PrintingFailed,
 // Tell the browser print preview failed.
 IPC_MESSAGE_ROUTED1(PrintHostMsg_PrintPreviewFailed,
                     int /* document cookie */)
+
+// Tell the browser print preview was cancelled.
+IPC_MESSAGE_ROUTED1(PrintHostMsg_PrintPreviewCancelled,
+                    int /* document cookie */)
diff --git a/chrome/renderer/mock_render_thread.cc b/chrome/renderer/mock_render_thread.cc
index de3daef..2535ff3 100644
--- a/chrome/renderer/mock_render_thread.cc
+++ b/chrome/renderer/mock_render_thread.cc
@@ -24,7 +24,8 @@ MockRenderThread::MockRenderThread()
       widget_(NULL),
       reply_deserializer_(NULL),
       printer_(new MockPrinter),
-      print_dialog_user_response_(true) {
+      print_dialog_user_response_(true),
+      cancel_print_preview_(false) {
 }
 
 MockRenderThread::~MockRenderThread() {
@@ -109,6 +110,8 @@ bool MockRenderThread::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPrintedPagesCount,
                         OnDidGetPrintedPagesCount)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidPrintPage, OnDidPrintPage)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_DidPreviewPage,
+                        OnDidPreviewPage)
 #if defined(OS_WIN)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DuplicateSection, OnDuplicateSection)
 #endif
@@ -209,6 +212,10 @@ void MockRenderThread::OnDidPrintPage(
     printer_->PrintPage(params);
 }
 
+void MockRenderThread::OnDidPreviewPage(int page_number, bool* cancel) {
+  *cancel = cancel_print_preview_;
+}
+
 void MockRenderThread::OnUpdatePrintSettings(
     int document_cookie,
     const DictionaryValue& job_settings,
@@ -234,3 +241,7 @@ void MockRenderThread::OnUpdatePrintSettings(
 void MockRenderThread::set_print_dialog_user_response(bool response) {
   print_dialog_user_response_ = response;
 }
+
+void MockRenderThread::set_cancel_print_preview(bool cancel) {
+  cancel_print_preview_ = cancel;
+}
diff --git a/chrome/renderer/mock_render_thread.h b/chrome/renderer/mock_render_thread.h
index 3be3134..3b359cf 100644
--- a/chrome/renderer/mock_render_thread.h
+++ b/chrome/renderer/mock_render_thread.h
@@ -83,6 +83,9 @@ class MockRenderThread : public RenderThreadBase {
   // False if the user decides to cancel.
   void set_print_dialog_user_response(bool response);
 
+  // Set to true to simulate canceling of a print preview.
+  void set_cancel_print_preview(bool cancel);
+
  private:
   // This function operates as a regular IPC listener.
   bool OnMessageReceived(const IPC::Message& msg);
@@ -121,6 +124,7 @@ class MockRenderThread : public RenderThreadBase {
 
   void OnDidGetPrintedPagesCount(int cookie, int number_pages);
   void OnDidPrintPage(const PrintHostMsg_DidPrintPage_Params& params);
+  void OnDidPreviewPage(int page_number, bool* cancel);
 
   // For print preview, PrintWebViewHelper will update settings.
   void OnUpdatePrintSettings(int document_cookie,
@@ -147,6 +151,9 @@ class MockRenderThread : public RenderThreadBase {
 
   // True to simulate user clicking print. False to cancel.
   bool print_dialog_user_response_;
+
+  // True to simulate cancelling a print preview.
+  bool cancel_print_preview_;
 };
 
 #endif  // CHROME_RENDERER_MOCK_RENDER_THREAD_H_
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index 8fcfd08..a918de7 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -398,7 +398,11 @@ void PrintWebViewHelper::DidFinishPrinting(PrintingResult result) {
     }
   } else if (result == FAIL_PREVIEW) {
     int cookie = print_pages_params_->params.document_cookie;
-    Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
+    if (notify_browser_of_print_failure_) {
+      Send(new PrintHostMsg_PrintPreviewFailed(routing_id(), cookie));
+    } else {
+      Send(new PrintHostMsg_PrintPreviewCancelled(routing_id(), cookie));
+    }
   }
 
   if (print_web_view_) {
@@ -449,12 +453,11 @@ bool PrintWebViewHelper::PrintPages(const PrintMsg_PrintPages_Params& params,
                                               node,
                                               frame->view());
   int page_count = prep_frame_view.GetExpectedPageCount();
-
+  if (!page_count)
+    return false;
   Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
                                                 printParams.document_cookie,
                                                 page_count));
-  if (!page_count)
-    return false;
 
   const gfx::Size& canvas_size = prep_frame_view.GetPrintCanvasSize();
   PrintMsg_PrintPage_Params page_params;
@@ -804,3 +807,11 @@ void PrintWebViewHelper::RequestPrintPreview() {
   old_print_pages_params_.reset();
   Send(new PrintHostMsg_RequestPrintPreview(routing_id()));
 }
+
+bool PrintWebViewHelper::PreviewPageRendered(int page_number) {
+  bool cancel = false;
+  Send(new PrintHostMsg_DidPreviewPage(routing_id(), page_number, &cancel));
+  if (cancel)
+    notify_browser_of_print_failure_ = false;
+  return !cancel;
+}
diff --git a/chrome/renderer/print_web_view_helper.h b/chrome/renderer/print_web_view_helper.h
index d477cc0..ba0d9e5 100644
--- a/chrome/renderer/print_web_view_helper.h
+++ b/chrome/renderer/print_web_view_helper.h
@@ -82,6 +82,7 @@ class PrintWebViewHelper : public RenderViewObserver,
                            BlockScriptInitiatedPrinting);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperTest, OnPrintPages);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperPreviewTest, OnPrintPreview);
+  FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperPreviewTest, OnPrintPreviewCancel);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperPreviewTest, OnPrintPreviewFail);
   FRIEND_TEST_ALL_PREFIXES(PrintWebViewHelperPreviewTest,
                            OnPrintForPrintPreview);
@@ -197,7 +198,6 @@ class PrintWebViewHelper : public RenderViewObserver,
   bool RenderPages(const PrintMsg_PrintPages_Params& params,
                    WebKit::WebFrame* frame,
                    WebKit::WebNode* node,
-                   bool send_expected_page_count,
                    int* page_count,
                    printing::Metafile* metafile,
                    bool is_preview);
@@ -255,6 +255,12 @@ class PrintWebViewHelper : public RenderViewObserver,
 
   void RequestPrintPreview();
 
+  // Called every time print preview renders a page. Notify the browser of the
+  // event and check if print preview should be cancelled. Returns false if
+  // print preview has been cancelled. |page_number| is 0-based, or negative to
+  // indicate its a cancel check only.
+  bool PreviewPageRendered(int page_number);
+
   WebKit::WebView* print_web_view_;
 
   // The frame to print for script initiated print preview.
diff --git a/chrome/renderer/print_web_view_helper_browsertest.cc b/chrome/renderer/print_web_view_helper_browsertest.cc
index 4ca40a4..1dd8e51 100644
--- a/chrome/renderer/print_web_view_helper_browsertest.cc
+++ b/chrome/renderer/print_web_view_helper_browsertest.cc
@@ -310,6 +310,13 @@ class PrintWebViewHelperPreviewTest : public PrintWebViewHelperTestBase {
   }
 
  protected:
+  void VerifyPrintPreviewCancelled(bool did_cancel) {
+    bool print_preview_cancelled =
+        (render_thread_.sink().GetUniqueMessageMatching(
+            PrintHostMsg_PrintPreviewCancelled::ID) != NULL);
+    EXPECT_EQ(did_cancel, print_preview_cancelled);
+  }
+
   void VerifyPrintPreviewFailed(bool did_fail) {
     bool print_preview_failed = (render_thread_.sink().GetUniqueMessageMatching(
         PrintHostMsg_PrintPreviewFailed::ID) != NULL);
@@ -350,11 +357,30 @@ TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreview) {
   CreatePrintSettingsDictionary(&dict);
   PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);
 
+  VerifyPrintPreviewCancelled(false);
   VerifyPrintPreviewFailed(false);
   VerifyPrintPreviewGenerated(true);
   VerifyPagesPrinted(false);
 }
 
+// Tests that cancelling a print preview works correctly.
+TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewCancel) {
+  LoadHTML(kPrintPreviewHTML);
+
+  // Cancel the print preview.
+  render_thread_.set_cancel_print_preview(true);
+
+  // Fill in some dummy values.
+  DictionaryValue dict;
+  CreatePrintSettingsDictionary(&dict);
+  PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);
+
+  VerifyPrintPreviewCancelled(true);
+  VerifyPrintPreviewFailed(false);
+  VerifyPrintPreviewGenerated(false);
+  VerifyPagesPrinted(false);
+}
+
 // Tests that print preview fails and receiving error messages through
 // that channel all works.
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewFail) {
@@ -364,6 +390,7 @@ TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewFail) {
   DictionaryValue empty_dict;
   PrintWebViewHelper::Get(view_)->OnPrintPreview(empty_dict);
 
+  VerifyPrintPreviewCancelled(false);
   VerifyPrintPreviewFailed(true);
   VerifyPrintPreviewGenerated(false);
   VerifyPagesPrinted(false);
diff --git a/chrome/renderer/print_web_view_helper_linux.cc b/chrome/renderer/print_web_view_helper_linux.cc
index ebbea61..9255a00 100644
--- a/chrome/renderer/print_web_view_helper_linux.cc
+++ b/chrome/renderer/print_web_view_helper_linux.cc
@@ -28,15 +28,16 @@ using WebKit::WebNode;
 bool PrintWebViewHelper::CreatePreviewDocument(
     const PrintMsg_PrintPages_Params& params, WebKit::WebFrame* frame,
     WebKit::WebNode* node) {
-  preview_page_count_ = 0;
+  if (!PreviewPageRendered(-1))
+    return false;
+
   printing::PreviewMetafile metafile;
   if (!metafile.Init())
     return false;
 
-  if (!RenderPages(params, frame, node, false, &preview_page_count_,
-                   &metafile, true)) {
+  preview_page_count_ = 0;
+  if (!RenderPages(params, frame, node, &preview_page_count_, &metafile, true))
     return false;
-  }
 
   // Get the size of the resulting metafile.
   uint32 buf_size = metafile.GetDataSize();
@@ -60,22 +61,13 @@ bool PrintWebViewHelper::CreatePreviewDocument(
 bool PrintWebViewHelper::PrintPages(const PrintMsg_PrintPages_Params& params,
                                     WebFrame* frame,
                                     WebNode* node) {
-  int page_count = 0;
-  bool send_expected_page_count =
-#if defined(OS_CHROMEOS)
-      false;
-#else
-      true;
-#endif  // defined(OS_CHROMEOS)
-
   printing::NativeMetafile metafile;
   if (!metafile.Init())
     return false;
 
-  if (!RenderPages(params, frame, node, send_expected_page_count, &page_count,
-                   &metafile, false)) {
+  int page_count = 0;
+  if (!RenderPages(params, frame, node, &page_count, &metafile, false))
     return false;
-  }
 
   // Get the size of the resulting metafile.
   uint32 buf_size = metafile.GetDataSize();
@@ -148,7 +140,6 @@ bool PrintWebViewHelper::PrintPages(const PrintMsg_PrintPages_Params& params,
 bool PrintWebViewHelper::RenderPages(const PrintMsg_PrintPages_Params& params,
                                      WebKit::WebFrame* frame,
                                      WebKit::WebNode* node,
-                                     bool send_expected_page_count,
                                      int* page_count,
                                      printing::Metafile* metafile,
                                      bool is_preview) {
@@ -158,14 +149,21 @@ bool PrintWebViewHelper::RenderPages(const PrintMsg_PrintPages_Params& params,
 
   PrepareFrameAndViewForPrint prep_frame_view(printParams, frame, node,
                                               frame->view());
+  if (is_preview && !PreviewPageRendered(-1))
+    return false;
+
   *page_count = prep_frame_view.GetExpectedPageCount();
-  if (send_expected_page_count) {
+  if (!*page_count)
+    return false;
+  if (is_preview) {
+    Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), *page_count));
+  } else {
+#if !defined(OS_CHROMEOS)
     Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
                                                   printParams.document_cookie,
                                                   *page_count));
+#endif
   }
-  if (!*page_count)
-    return false;
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   base::TimeTicks page_begin_time = begin_time;
@@ -179,6 +177,8 @@ bool PrintWebViewHelper::RenderPages(const PrintMsg_PrintPages_Params& params,
       PrintPageInternal(page_params, canvas_size, frame, metafile);
       if (is_preview) {
         page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+        if (!PreviewPageRendered(i))
+          return false;
       }
     }
   } else {
@@ -187,6 +187,8 @@ bool PrintWebViewHelper::RenderPages(const PrintMsg_PrintPages_Params& params,
       PrintPageInternal(page_params, canvas_size, frame, metafile);
       if (is_preview) {
         page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+        if (!PreviewPageRendered(params.pages[i]))
+          return false;
       }
     }
   }
diff --git a/chrome/renderer/print_web_view_helper_mac.mm b/chrome/renderer/print_web_view_helper_mac.mm
index aab653d..54521ff 100644
--- a/chrome/renderer/print_web_view_helper_mac.mm
+++ b/chrome/renderer/print_web_view_helper_mac.mm
@@ -62,15 +62,22 @@ void PrintWebViewHelper::PrintPageInternal(
 bool PrintWebViewHelper::CreatePreviewDocument(
     const PrintMsg_PrintPages_Params& params, WebKit::WebFrame* frame,
     WebKit::WebNode* node) {
+  if (!PreviewPageRendered(-1))
+    return false;
+
   PrintMsg_Print_Params printParams = params.params;
   UpdatePrintableSizeInPrintParameters(frame, node, &printParams);
 
   PrepareFrameAndViewForPrint prep_frame_view(printParams,
                                               frame, node, frame->view());
-  preview_page_count_ = prep_frame_view.GetExpectedPageCount();
+  if (!PreviewPageRendered(-1))
+    return false;
 
+  preview_page_count_ = prep_frame_view.GetExpectedPageCount();
   if (!preview_page_count_)
     return false;
+  Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(),
+                                               preview_page_count_));
 
   printing::PreviewMetafile metafile;
   if (!metafile.Init())
@@ -89,14 +96,18 @@ bool PrintWebViewHelper::CreatePreviewDocument(
       RenderPage(printParams.page_size, content_area, scale_factor, i, frame,
                  &metafile);
       page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+      if (!PreviewPageRendered(i))
+        return false;
     }
   } else {
     for (size_t i = 0; i < params.pages.size(); ++i) {
       if (params.pages[i] >= preview_page_count_)
         break;
       RenderPage(printParams.page_size, content_area, scale_factor,
-                 static_cast<int>(params.pages[i]), frame, &metafile);
+                 params.pages[i], frame, &metafile);
       page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+      if (!PreviewPageRendered(params.pages[i]))
+        return false;
     }
   }
 
diff --git a/chrome/renderer/print_web_view_helper_win.cc b/chrome/renderer/print_web_view_helper_win.cc
index 5514780..9528797 100644
--- a/chrome/renderer/print_web_view_helper_win.cc
+++ b/chrome/renderer/print_web_view_helper_win.cc
@@ -5,9 +5,9 @@
 #include "chrome/renderer/print_web_view_helper.h"
 
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
-#include "base/scoped_ptr.h"
 #include "chrome/common/print_messages.h"
 #include "printing/metafile.h"
 #include "printing/metafile_impl.h"
@@ -126,13 +126,21 @@ void PrintWebViewHelper::PrintPageInternal(
 bool PrintWebViewHelper::CreatePreviewDocument(
     const PrintMsg_PrintPages_Params& params, WebKit::WebFrame* frame,
     WebKit::WebNode* node) {
+  if (!PreviewPageRendered(-1))
+    return false;
+
   PrintMsg_Print_Params print_params = params.params;
   UpdatePrintableSizeInPrintParameters(frame, node, &print_params);
   PrepareFrameAndViewForPrint prep_frame_view(print_params, frame, node,
                                               frame->view());
+  if (!PreviewPageRendered(-1))
+    return false;
+
   preview_page_count_ = prep_frame_view.GetExpectedPageCount();
   if (!preview_page_count_)
     return false;
+  Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(),
+                                               preview_page_count_));
 
   scoped_ptr<Metafile> metafile(new printing::PreviewMetafile);
   metafile->Init();
@@ -149,15 +157,19 @@ bool PrintWebViewHelper::CreatePreviewDocument(
       float scale_factor = shrink;
       RenderPage(print_params, &scale_factor, i, true, frame, &metafile);
       page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+      if (!PreviewPageRendered(i))
+        return false;
     }
   } else {
     for (size_t i = 0; i < params.pages.size(); ++i) {
       if (params.pages[i] >= preview_page_count_)
         break;
       float scale_factor = shrink;
-      RenderPage(print_params, &scale_factor,
-                 static_cast<int>(params.pages[i]), true, frame, &metafile);
+      RenderPage(print_params, &scale_factor, params.pages[i], true, frame,
+                 &metafile);
       page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
+      if (!PreviewPageRendered(params.pages[i]))
+        return false;
     }
   }