Pass printing result to the browser.

The resulting PDF file will now be passed to the browser and be saved as "chromium_printing_test.pdf" under current directory.

BUG=9847
TEST=printing on linux should now generate chromium_printing_test.pdf in download directory. Printing on Windows should still work.

Patch contributed by minyu.huang@gmail.com
Review URL: http://codereview.chromium.org/172115

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25615 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 257 insertions, 61 deletions

diff --git a/chrome/browser/renderer_host/resource_message_filter.cc b/chrome/browser/renderer_host/resource_message_filter.cc
index b460814..059f2af 100644
--- a/chrome/browser/renderer_host/resource_message_filter.cc
+++ b/chrome/browser/renderer_host/resource_message_filter.cc
@@ -323,7 +323,13 @@ bool ResourceMessageFilter::OnMessageReceived(const IPC::Message& msg) {
                           OnGetPreferredExtensionForMimeType)
       IPC_MESSAGE_HANDLER(ViewHostMsg_GetCPBrowsingContext,
                           OnGetCPBrowsingContext)
+#if defined(OS_WIN)
       IPC_MESSAGE_HANDLER(ViewHostMsg_DuplicateSection, OnDuplicateSection)
+#endif
+#if defined(OS_LINUX)
+      IPC_MESSAGE_HANDLER(ViewHostMsg_AllocateShareMemory,
+                          OnAllocateShareMemory)
+#endif
       IPC_MESSAGE_HANDLER(ViewHostMsg_ResourceTypeStats, OnResourceTypeStats)
       IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_ResolveProxy, OnResolveProxy)
       IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_GetDefaultPrintSettings,
@@ -675,6 +681,7 @@ void ResourceMessageFilter::OnGetCPBrowsingContext(uint32* context) {
       CPBrowsingContextManager::Instance()->Allocate(request_context_.get());
 }
 
+#if defined(OS_WIN)
 void ResourceMessageFilter::OnDuplicateSection(
     base::SharedMemoryHandle renderer_handle,
     base::SharedMemoryHandle* browser_handle) {
@@ -683,6 +690,30 @@ void ResourceMessageFilter::OnDuplicateSection(
   base::SharedMemory shared_buf(renderer_handle, true, handle());
   shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), browser_handle);
 }
+#endif
+
+#if defined(OS_LINUX)
+void ResourceMessageFilter::OnAllocateShareMemory(
+    size_t buffer_size,
+    base::SharedMemoryHandle* browser_handle) {
+  // We don't want to allocate a super big chunk of memory.
+  // 32MB should be large enough for printing on Linux.
+  if (buffer_size > 32 * 1024 * 1024) {
+    *browser_handle = base::SharedMemory::NULLHandle();
+    NOTREACHED() << "Buffer too large: " << buffer_size;
+    return;
+  }
+  base::SharedMemory shared_buf;
+  shared_buf.Create(L"", false, false, buffer_size);
+  if (shared_buf.Map(buffer_size)) {
+    shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), browser_handle);
+  } else {
+    *browser_handle = base::SharedMemory::NULLHandle();
+    NOTREACHED() << "Cannot map buffer";
+    return;
+  }
+}
+#endif
 
 void ResourceMessageFilter::OnResourceTypeStats(
     const WebCache::ResourceTypeStats& stats) {
diff --git a/chrome/browser/renderer_host/resource_message_filter.h b/chrome/browser/renderer_host/resource_message_filter.h
index 825422b..7fd7979 100644
--- a/chrome/browser/renderer_host/resource_message_filter.h
+++ b/chrome/browser/renderer_host/resource_message_filter.h
@@ -5,6 +5,10 @@
 #ifndef CHROME_BROWSER_RENDERER_HOST_RESOURCE_MSG_FILTER_H_
 #define CHROME_BROWSER_RENDERER_HOST_RESOURCE_MSG_FILTER_H_
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 #include <string>
 #include <vector>
 
@@ -26,10 +30,6 @@
 #include "ipc/ipc_channel_proxy.h"
 #include "webkit/api/public/WebCache.h"
 
-#if defined(OS_WIN)
-#include <windows.h>
-#endif
-
 class AppCacheDispatcherHost;
 class AudioRendererHost;
 class Clipboard;
@@ -190,8 +190,20 @@ class ResourceMessageFilter : public IPC::ChannelProxy::MessageFilter,
   void OnGetPreferredExtensionForMimeType(const std::string& mime_type,
                                           FilePath::StringType* ext);
   void OnGetCPBrowsingContext(uint32* context);
+
+#if defined(OS_WIN)
+  // Used to pass resulting EMF from renderer to browser in printing.
   void OnDuplicateSection(base::SharedMemoryHandle renderer_handle,
                           base::SharedMemoryHandle* browser_handle);
+#endif
+
+#if defined(OS_LINUX)
+  // Used to ask the browser allocate a block of shared memory for the renderer
+  // to fill in resulting PDF in renderer.
+  void OnAllocateShareMemory(size_t buffer_size,
+                             base::SharedMemoryHandle* browser_handle);
+#endif
+
   void OnResourceTypeStats(const WebKit::WebCache::ResourceTypeStats& stats);
 
   void OnResolveProxy(const GURL& url, IPC::Message* reply_msg);
diff --git a/chrome/common/render_messages_internal.h b/chrome/common/render_messages_internal.h
index 293ce43..43b2b9c 100644
--- a/chrome/common/render_messages_internal.h
+++ b/chrome/common/render_messages_internal.h
@@ -1338,11 +1338,21 @@ IPC_BEGIN_MESSAGES(ViewHost)
   IPC_MESSAGE_ROUTED1(ViewHostMsg_UploadProgress_ACK,
                       int /* request_id */)
 
+#if defined(OS_WIN)
   // Duplicates a shared memory handle from the renderer to the browser. Then
   // the renderer can flush the handle.
   IPC_SYNC_MESSAGE_ROUTED1_1(ViewHostMsg_DuplicateSection,
                              base::SharedMemoryHandle /* renderer handle */,
                              base::SharedMemoryHandle /* browser handle */)
+#endif
+
+#if defined(OS_LINUX)
+  // Asks the browser create a block of shared memory for the renderer to fill
+  // in resulting NativeMetafile in printing.
+  IPC_SYNC_MESSAGE_ROUTED1_1(ViewHostMsg_AllocateShareMemory,
+                             size_t /* buffer size */,
+                             base::SharedMemoryHandle /* browser handle */)
+#endif
 
   // Provide the browser process with information about the WebCore resource
   // cache.
diff --git a/chrome/common/temp_scaffolding_stubs.cc b/chrome/common/temp_scaffolding_stubs.cc
index f2d8afb..4357d99 100644
--- a/chrome/common/temp_scaffolding_stubs.cc
+++ b/chrome/common/temp_scaffolding_stubs.cc
@@ -4,8 +4,6 @@
 
 #include "chrome/common/temp_scaffolding_stubs.h"
 
-#include "build/build_config.h"
-
 #include <vector>
 
 #include "base/gfx/rect.h"
@@ -15,7 +13,12 @@
 #include "chrome/browser/rlz/rlz.h"
 
 #if defined(OS_LINUX)
+#include "base/path_service.h"
 #include "chrome/browser/dock_info.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/render_messages.h"
+#include "printing/native_metafile.h"
 #endif
 
 #if defined(OS_MACOSX)
@@ -322,3 +325,48 @@ void BookmarkManager::Show(Profile* profile) {
 }
 
 #endif
+
+//------------------------------------------------------------------------------
+
+#if defined(OS_LINUX)
+// TODO(myhuang): This is a quick hack for testing purpose. We should implement
+// PrintViewManager and other related classes later on Linux.
+namespace printing {
+
+void PrintViewManager::DidPrintPage(
+    const ViewHostMsg_DidPrintPage_Params& params) {
+  base::SharedMemory shared_buf(params.metafile_data_handle, true);
+  if (!shared_buf.Map(params.data_size)) {
+    NOTREACHED() << "couldn't map";
+    owner_.Stop();
+    return;
+  }
+
+  // The only format we can use now is PDF since Cairo needs to create a
+  // temporary file for a PostScript surface. We do not allow disk I/O in the
+  // renderer.
+  scoped_ptr<NativeMetafile> metafile(
+      new NativeMetafile(printing::NativeMetafile::PDF));
+
+  if (!metafile->Init(shared_buf.memory(), params.data_size)) {
+    NOTREACHED() << "Invalid metafile header";
+    shared_buf.Unmap();
+    owner_.Stop();
+    return;
+  }
+
+  // Save the PDF file to default download location.
+  // NOTE: Existing file will be overwritten.
+  FilePath default_save_path;
+  if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &default_save_path)) {
+    NOTREACHED();
+  }
+  FilePath save_filename =
+      default_save_path.Append(FilePath("chromium_printing_test.pdf"));
+  metafile->SaveTo(save_filename);
+  shared_buf.Unmap();
+}
+
+}  // namespace printing
+
+#endif
diff --git a/chrome/common/temp_scaffolding_stubs.h b/chrome/common/temp_scaffolding_stubs.h
index 2ed3181..7b01f31 100644
--- a/chrome/common/temp_scaffolding_stubs.h
+++ b/chrome/common/temp_scaffolding_stubs.h
@@ -54,7 +54,7 @@ namespace printing {
 
 class PrintViewManager : public RenderViewHostDelegate::Printing {
  public:
-  PrintViewManager(TabContents&) { }
+  PrintViewManager(TabContents& owner) : owner_(owner) { }
   void Stop() { NOTIMPLEMENTED(); }
   void Destroy() { }
   bool OnRenderViewGone(RenderViewHost*) {
@@ -66,9 +66,17 @@ class PrintViewManager : public RenderViewHostDelegate::Printing {
   virtual void DidGetPrintedPagesCount(int cookie, int number_pages) {
     NOTIMPLEMENTED();
   }
+
+#if defined(OS_LINUX)
+  virtual void DidPrintPage(const ViewHostMsg_DidPrintPage_Params& params);
+#else
   virtual void DidPrintPage(const ViewHostMsg_DidPrintPage_Params& params) {
     NOTIMPLEMENTED();
   }
+#endif
+
+ private:
+  TabContents& owner_;
 };
 
 class PrintingContext {
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index d23bef2..9de27a8 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -29,7 +29,6 @@ PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
     WebFrame* frame,
     WebView* web_view)
         : frame_(frame), web_view_(web_view), expected_pages_count_(0) {
-
   print_canvas_size_.set_width(
       printing::ConvertUnit(print_params.printable_size.width(),
                             static_cast<int>(print_params.dpi),
@@ -114,33 +113,6 @@ bool PrintWebViewHelper::CopyAndPrint(const ViewMsg_PrintPages_Params& params,
   return true;
 }
 
-void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
-                                    WebFrame* frame) {
-  PrepareFrameAndViewForPrint prep_frame_view(params.params,
-                                              frame,
-                                              frame->view());
-  int page_count = prep_frame_view.GetExpectedPageCount();
-
-  Send(new ViewHostMsg_DidGetPrintedPagesCount(routing_id(),
-                                               params.params.document_cookie,
-                                               page_count));
-  if (page_count) {
-    ViewMsg_PrintPage_Params page_params;
-    page_params.params = params.params;
-    if (params.pages.empty()) {
-      for (int i = 0; i < page_count; ++i) {
-        page_params.page_number = i;
-        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
-      }
-    } else {
-      for (size_t i = 0; i < params.pages.size(); ++i) {
-        page_params.page_number = params.pages[i];
-        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
-      }
-    }
-  }
-}
-
 void PrintWebViewHelper::PrintPageAsJPEG(
     const ViewMsg_PrintPage_Params& params,
     WebFrame* frame,
diff --git a/chrome/renderer/print_web_view_helper.h b/chrome/renderer/print_web_view_helper.h
index 406c807..63a973b 100644
--- a/chrome/renderer/print_web_view_helper.h
+++ b/chrome/renderer/print_web_view_helper.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_RENDERER_PRINT_WEB_VIEW_DELEGATE_H_
-#define CHROME_RENDERER_PRINT_WEB_VIEW_DELEGATE_H_
+#ifndef CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
+#define CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 
 #include <vector>
 
@@ -20,6 +20,13 @@ namespace IPC {
 class Message;
 }
 
+#if defined(OS_LINUX)
+namespace printing {
+class PdfPsMetafile;
+typedef PdfPsMetafile NativeMetafile;
+}
+#endif
+
 class RenderView;
 class WebView;
 struct ViewMsg_Print_Params;
@@ -88,9 +95,16 @@ class PrintWebViewHelper : public WebViewDelegate {
                     WebKit::WebFrame* web_frame);
 
   // Prints the page listed in |params|.
+#if defined(OS_LINUX)
+  void PrintPage(const ViewMsg_PrintPage_Params& params,
+                 const gfx::Size& canvas_size,
+                 WebKit::WebFrame* frame,
+                 printing::NativeMetafile* metafile);
+#else
   void PrintPage(const ViewMsg_PrintPage_Params& params,
                  const gfx::Size& canvas_size,
                  WebKit::WebFrame* frame);
+#endif
 
   // Prints all the pages listed in |params|.
   // It will implicitly revert the document to display CSS media type.
@@ -129,4 +143,4 @@ class PrintWebViewHelper : public WebViewDelegate {
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
-#endif  // CHROME_RENDERER_PRINT_WEB_VIEW_DELEGATE_H_
+#endif  // CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
diff --git a/chrome/renderer/print_web_view_helper_linux.cc b/chrome/renderer/print_web_view_helper_linux.cc
index 0fb7ffc..b16b05e 100644
--- a/chrome/renderer/print_web_view_helper_linux.cc
+++ b/chrome/renderer/print_web_view_helper_linux.cc
@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "chrome/common/render_messages.h"
+#include "printing/native_metafile.h"
 #include "skia/ext/vector_canvas.h"
 #include "webkit/api/public/WebFrame.h"
 
@@ -37,30 +38,85 @@ void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
   default_settings.document_cookie = NULL;
   default_settings.selection_only = false;
 
-  // Calculate the estimated page count.
-  PrepareFrameAndViewForPrint prep_frame_view(default_settings,
+  ViewMsg_PrintPages_Params print_settings;
+  print_settings.params = default_settings;
+
+  PrintPages(print_settings, frame);
+}
+
+void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
+                                    WebFrame* frame) {
+  PrepareFrameAndViewForPrint prep_frame_view(params.params,
                                               frame,
                                               frame->view());
-  int expected_pages_count = prep_frame_view.GetExpectedPageCount();
-  DCHECK(expected_pages_count);
+  int page_count = prep_frame_view.GetExpectedPageCount();
+
+  // TODO(myhuang): Send ViewHostMsg_DidGetPrintedPagesCount.
+
+  if (page_count) {
+    // We only can use PDF in the renderer because Cairo needs to create a
+    // temporary file for a PostScript surface.
+    printing::NativeMetafile metafile(printing::NativeMetafile::PDF);
+    metafile.Init();
+
+    ViewMsg_PrintPage_Params print_page_params;
+    print_page_params.params = params.params;
+    const gfx::Size& canvas_size = prep_frame_view.GetPrintCanvasSize();
+    if (params.pages.empty()) {
+      for (int i = 0; i < page_count; ++i) {
+        print_page_params.page_number = i;
+        PrintPage(print_page_params, canvas_size, frame, &metafile);
+      }
+    } else {
+      for (size_t i = 0; i < params.pages.size(); ++i) {
+        print_page_params.page_number = params.pages[i];
+        PrintPage(print_page_params, canvas_size, frame, &metafile);
+      }
+    }
+
+    metafile.Close();
 
-  ViewMsg_PrintPage_Params page_params;
-  page_params.params = default_settings;
+    // Get the size of the resulting metafile.
+    unsigned int buf_size = metafile.GetDataSize();
+    DCHECK_GT(buf_size, 0u);
 
-  // TODO(myhuang): Get final printing settings via IPC.
-  // For testing purpose, we hard-coded printing settings here.
+    ViewHostMsg_DidPrintPage_Params did_page_params;
 
-  // Print the first page only.
-  expected_pages_count = 1;
-  for (int i = 0; i < expected_pages_count; ++i) {
-    page_params.page_number = i;
-    PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
+    // Ask the browser create the shared memory for us.
+    if (Send(new ViewHostMsg_AllocateShareMemory(
+            routing_id(),
+            buf_size,
+            &did_page_params.metafile_data_handle))) {
+      if (did_page_params.metafile_data_handle.fd > -1) {
+        base::SharedMemory shared_buf(did_page_params.metafile_data_handle,
+                                      false);
+        if (shared_buf.Map(buf_size)) {
+          if (metafile.GetData(shared_buf.memory(), buf_size)) {
+            // FIXME(myhuang): This is for testing purpose at this moment.
+            // We use this message to pass the resulting PDF to the browser,
+            // and the browser will save this PDF on the disk.
+            did_page_params.data_size = buf_size;
+            Send(new ViewHostMsg_DidPrintPage(routing_id(), did_page_params));
+          } else {
+            NOTREACHED() << "GetData() failed";
+          }
+          shared_buf.Unmap();
+        } else {
+          NOTREACHED() << "Buffer mapping failed";
+        }
+      } else {
+        NOTREACHED() << "Buffer allocation failed";
+      }
+    } else {
+      NOTREACHED() << "Buffer allocation failed";
+    }
   }
 }
 
 void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
                                    const gfx::Size& canvas_size,
-                                   WebFrame* frame) {
+                                   WebFrame* frame,
+                                   printing::NativeMetafile* metafile) {
   // Since WebKit extends the page width depending on the magical shrink
   // factor we make sure the canvas covers the worst case scenario
   // (x2.0 currently).  PrintContext will then set the correct clipping region.
@@ -71,16 +127,29 @@ void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
   float shrink = static_cast<float>(canvas_size.width()) /
       params.params.printable_size.width();
 
-  // TODO(myhuang): We now use VectorCanvas to generate a PS/PDF file for
-  // each page in printing. We might also need to create a metafile class
-  // on Linux.
-  skia::VectorCanvas canvas(size_x, size_y);
+  cairo_t* cairo_context = metafile->StartPage(size_x, size_y);
+  if (!cairo_context) {
+    // TODO(myhuang): We should handle such kind of error further!
+    // We already have had DLOG(ERROR) in NativeMetafile::StartPage(),
+    // log the error here, too?
+    return;
+  }
+
+  skia::VectorCanvas canvas(cairo_context, size_x, size_y);
   float webkit_shrink = frame->printPage(params.page_number, &canvas);
-  if (shrink <= 0) {
+  if (webkit_shrink <= 0) {
     NOTREACHED() << "Printing page " << params.page_number << " failed.";
   } else {
     // Update the dpi adjustment with the "page shrink" calculated in webkit.
     shrink /= webkit_shrink;
   }
+
+  // TODO(myhuang): We should handle transformation for paper margins.
+  // TODO(myhuang): We should render the header and the footer.
+
+  // Done printing. Close the device context to retrieve the compiled metafile.
+  if (!metafile->FinishPage(shrink)) {
+    NOTREACHED() << "metafile failed";
+  }
 }
 
diff --git a/chrome/renderer/print_web_view_helper_mac.cc b/chrome/renderer/print_web_view_helper_mac.cc
index 87a5517..fdb61419e 100644
--- a/chrome/renderer/print_web_view_helper_mac.cc
+++ b/chrome/renderer/print_web_view_helper_mac.cc
@@ -13,6 +13,12 @@ void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
   NOTIMPLEMENTED();
 }
 
+void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
+                                    WebKit::WebFrame* frame) {
+  // TODO(port) implement printing
+  NOTIMPLEMENTED();
+}
+
 void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
                                    const gfx::Size& canvas_size,
                                    WebFrame* frame) {
diff --git a/chrome/renderer/print_web_view_helper_win.cc b/chrome/renderer/print_web_view_helper_win.cc
index 625a66d..dba857e 100644
--- a/chrome/renderer/print_web_view_helper_win.cc
+++ b/chrome/renderer/print_web_view_helper_win.cc
@@ -11,6 +11,7 @@
 #include "chrome/renderer/render_view.h"
 #include "grit/generated_resources.h"
 #include "printing/native_metafile.h"
+#include "skia/ext/vector_canvas.h"
 #include "webkit/api/public/WebConsoleMessage.h"
 #include "webkit/api/public/WebFrame.h"
 
@@ -18,8 +19,6 @@ using WebKit::WebConsoleMessage;
 using WebKit::WebFrame;
 using WebKit::WebString;
 
-#include "skia/ext/vector_canvas.h"
-
 void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
   const int kMinSecondsToIgnoreJavascriptInitiatedPrint = 2;
   const int kMaxSecondsToIgnoreJavascriptInitiatedPrint = 2 * 60;  // 2 Minutes.
@@ -149,6 +148,33 @@ void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
   DidFinishPrinting(user_cancelled_print);
 }
 
+void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
+                                    WebFrame* frame) {
+  PrepareFrameAndViewForPrint prep_frame_view(params.params,
+                                              frame,
+                                              frame->view());
+  int page_count = prep_frame_view.GetExpectedPageCount();
+
+  Send(new ViewHostMsg_DidGetPrintedPagesCount(routing_id(),
+                                               params.params.document_cookie,
+                                               page_count));
+  if (page_count) {
+    ViewMsg_PrintPage_Params page_params;
+    page_params.params = params.params;
+    if (params.pages.empty()) {
+      for (int i = 0; i < page_count; ++i) {
+        page_params.page_number = i;
+        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
+      }
+    } else {
+      for (size_t i = 0; i < params.pages.size(); ++i) {
+        page_params.page_number = params.pages[i];
+        PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
+      }
+    }
+  }
+}
+
 void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
                                 const gfx::Size& canvas_size,
                                 WebFrame* frame) {
@@ -177,7 +203,7 @@ void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
   skia::PlatformCanvas canvas(size_x, size_y, true);
   canvas.drawARGB(255, 255, 255, 255, SkPorterDuff::kSrc_Mode);
   float webkit_shrink = frame->PrintPage(params.page_number, &canvas);
-  if (shrink <= 0) {
+  if (shrink <= 0 || webkit_shrink <= 0) {
     NOTREACHED() << "Printing page " << params.page_number << " failed.";
   } else {
     // Update the dpi adjustment with the "page shrink" calculated in webkit.
@@ -204,7 +230,7 @@ void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
   // 100% GDI based.
   skia::VectorCanvas canvas(hdc, size_x, size_y);
   float webkit_shrink = frame->printPage(params.page_number, &canvas);
-  if (shrink <= 0) {
+  if (shrink <= 0 || webkit_shrink <= 0) {
     NOTREACHED() << "Printing page " << params.page_number << " failed.";
   } else {
     // Update the dpi adjustment with the "page shrink" calculated in webkit.