PdfMetafileSkia gives out a SkCanvas, not a SkBaseDevice.

printing/pdf_metafile_skia.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "printing/pdf_metafile_skia.h"
 
 #include "base/containers/hash_tables.h"
 #include "base/files/file_util.h"
 #include "base/metrics/histogram.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/posix/eintr_wrapper.h"
 #include "skia/ext/refptr.h"
-#include "skia/ext/vector_platform_device_skia.h"
+#include "skia/ext/vector_canvas.h"
 #include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "third_party/skia/include/core/SkScalar.h"
 #include "third_party/skia/include/core/SkStream.h"
 #include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/skia/include/pdf/SkPDFDevice.h"
 #include "third_party/skia/include/pdf/SkPDFDocument.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
 #if defined(OS_MACOSX)
 #include "printing/pdf_metafile_cg_mac.h"
 #endif
 
 #if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
 #endif
 
 namespace printing {
 
 struct PdfMetafileSkiaData {
+  // True when finish page is outstanding for current page.
+  bool PageOutstanding() { return current_page_canvas_; }

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

Can you make it pure struct without methods?
I see no problem with checking data_->current_page_canvas_

[hal.canary, 2014/11/05 23:10:58]

Done.

+
   skia::RefPtr<SkPDFDevice> current_page_;
+  skia::RefPtr<SkCanvas> current_page_canvas_;
   SkPDFDocument pdf_doc_;
   SkDynamicMemoryWStream pdf_stream_;
 #if defined(OS_MACOSX)
   PdfMetafileCg pdf_cg_;
 #endif
 };
 
 PdfMetafileSkia::~PdfMetafileSkia() {}
 
 bool PdfMetafileSkia::Init() {
   return true;
 }
 bool PdfMetafileSkia::InitFromData(const void* src_buffer,
                                    uint32 src_buffer_size) {
   return data_->pdf_stream_.write(src_buffer, src_buffer_size);
 }
 
-SkBaseDevice* PdfMetafileSkia::StartPageForVectorCanvas(
-    const gfx::Size& page_size, const gfx::Rect& content_area,
-    const float& scale_factor) {
-  DCHECK(!page_outstanding_);
-  page_outstanding_ = true;
+bool PdfMetafileSkia::StartPage(const gfx::Size& page_size,
+                                const gfx::Rect& content_area,
+                                const float& scale_factor) {
+  DCHECK(!data_->PageOutstanding());
 
   // Adjust for the margins and apply the scale factor.
   SkMatrix transform;
   transform.setTranslate(SkIntToScalar(content_area.x()),
                          SkIntToScalar(content_area.y()));
   transform.preScale(SkFloatToScalar(scale_factor),
                      SkFloatToScalar(scale_factor));
 
   SkISize pdf_page_size = SkISize::Make(page_size.width(), page_size.height());
   SkISize pdf_content_size =
       SkISize::Make(content_area.width(), content_area.height());
+
   skia::RefPtr<SkPDFDevice> pdf_device =

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

can you just assing directly into data_->current_page_

[hal.canary, 2014/11/05 23:10:58]

Done.

-      skia::AdoptRef(new skia::VectorPlatformDeviceSkia(
+      skia::AdoptRef(new SkPDFDevice(
           pdf_page_size, pdf_content_size, transform));
   data_->current_page_ = pdf_device;
-  return pdf_device.get();
+  data_->current_page_canvas_ =
+      skia::AdoptRef(new SkCanvas(data_->current_page_.get()));
+  return true;
 }
 
-bool PdfMetafileSkia::StartPage(const gfx::Size& page_size,
-                                const gfx::Rect& content_area,
-                                const float& scale_factor) {
-  NOTREACHED();
-  return false;
+skia::VectorCanvas* PdfMetafileSkia::GetVectorCanvasForNewPage(
+    const gfx::Size& page_size, const gfx::Rect& content_area,

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

seems running "git cl format" may fix this formatting.

[hal.canary, 2014/11/05 23:10:58]

Done.

For some reason I had to `chmod +x buildtools/linux64/clang-format` before this
worked.

+    const float& scale_factor) {
+  (void)this->StartPage(page_size, content_area, scale_factor);

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

if (!StartPage(page_size, content_area, scale_factor))
  return nullptr.

[hal.canary, 2014/11/05 23:10:58]

Done.

+  return data_->current_page_canvas_.get();
 }
 
 bool PdfMetafileSkia::FinishPage() {
+  DCHECK(data_->PageOutstanding());
   DCHECK(data_->current_page_.get());
 
+  data_->current_page_canvas_.clear();  // Unref SkCanvas.
   data_->pdf_doc_.appendPage(data_->current_page_.get());
-  page_outstanding_ = false;
   return true;
 }
 
 bool PdfMetafileSkia::FinishDocument() {
   // Don't do anything if we've already set the data in InitFromData.
   if (data_->pdf_stream_.getOffset())
     return true;
 
-  if (page_outstanding_)
+  if (data_->PageOutstanding())
     FinishPage();
 
   data_->current_page_.clear();
 
   int font_counts[SkAdvancedTypefaceMetrics::kOther_Font + 2];
   data_->pdf_doc_.getCountOfFontTypes(font_counts);
   for (int type = 0;
        type <= SkAdvancedTypefaceMetrics::kOther_Font + 1;
        type++) {
     for (int count = 0; count < font_counts[type]; count++) {
@@ skipping 64 matching lines @@
                                  const MacRenderPageParams& params) const {
   DCHECK_GT(data_->pdf_stream_.getOffset(), 0U);
   if (data_->pdf_cg_.GetDataSize() == 0) {
     SkAutoDataUnref data(data_->pdf_stream_.copyToData());
     data_->pdf_cg_.InitFromData(data->bytes(), data->size());
   }
   return data_->pdf_cg_.RenderPage(page_number, context, rect, params);
 }
 #endif
 
+bool PdfMetafileSkia::SaveTo(base::File* file) const {
+  DCHECK(file);

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

no need DCHECK here. It will crash on file-> anyway.

[hal.canary, 2014/11/05 23:10:58]

Done.

+  if (GetDataSize() == 0U)
+    return false;
+  SkAutoDataUnref data(data_->pdf_stream_.copyToData());
+  // TODO(halcanary): rewrite this function without extra data copy
+  // using SkStreamAsset.
+  const char* ptr = reinterpret_cast<const char*>(data->data());
+  int size = base::checked_cast<int>(data->size());
+  return file->WriteAtCurrentPos(ptr, size) == size;
+}
+
 #if defined(OS_CHROMEOS) || defined(OS_ANDROID)
 bool PdfMetafileSkia::SaveToFD(const base::FileDescriptor& fd) const {
   DCHECK_GT(data_->pdf_stream_.getOffset(), 0U);
 
   if (fd.fd < 0) {
     DLOG(ERROR) << "Invalid file descriptor!";
     return false;
   }
   base::File file(fd.fd);
-  SkAutoDataUnref data(data_->pdf_stream_.copyToData());
-  bool result =
-      file.WriteAtCurrentPos(reinterpret_cast<const char*>(data->data()),
-                             GetDataSize()) == static_cast<int>(GetDataSize());
+  bool result = this->SaveTo(&file);

[Vitaly Buka (NO REVIEWS), 2014/11/05 22:21:38]

no need this->

[hal.canary, 2014/11/05 23:10:58]

Done.

   DLOG_IF(ERROR, !result) << "Failed to save file with fd " << fd.fd;
 
   if (!fd.auto_close)
     file.TakePlatformFile();
   return result;
 }
 #endif
 
 PdfMetafileSkia::PdfMetafileSkia()
-    : data_(new PdfMetafileSkiaData),
-      page_outstanding_(false) {
+    : data_(new PdfMetafileSkiaData) {
 }
 
 scoped_ptr<PdfMetafileSkia> PdfMetafileSkia::GetMetafileForCurrentPage() {
   scoped_ptr<PdfMetafileSkia> metafile;
   SkPDFDocument pdf_doc(SkPDFDocument::kDraftMode_Flags);
   if (!pdf_doc.appendPage(data_->current_page_.get()))
     return metafile.Pass();
 
   SkDynamicMemoryWStream pdf_stream;
   if (!pdf_doc.emitPDF(&pdf_stream))
     return metafile.Pass();
 
   SkAutoDataUnref data_copy(pdf_stream.copyToData());
   if (data_copy->size() == 0)
     return scoped_ptr<PdfMetafileSkia>();
 
   metafile.reset(new PdfMetafileSkia);
   if (!metafile->InitFromData(data_copy->bytes(),
                               base::checked_cast<uint32>(data_copy->size()))) {
     metafile.reset();
   }
   return metafile.Pass();
 }
 
 }  // namespace printing