Add testing flag for XPS for deterministic ids.

include/device/xps/SkXPSDevice.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkXPSDevice_DEFINED
 #define SkXPSDevice_DEFINED
 
 #include "SkTypes.h"
 #include <ObjBase.h>
 #include <XpsObjectModel.h>
 
 #include "SkAutoCoInitialize.h"
 #include "SkBitmapDevice.h"
 #include "SkBitSet.h"
 #include "SkCanvas.h"
 #include "SkColor.h"
 #include "SkPaint.h"
 #include "SkPath.h"
 #include "SkPoint.h"
 #include "SkShader.h"
 #include "SkSize.h"
 #include "SkTArray.h"
 #include "SkTScopedComPtr.h"
 #include "SkTypeface.h"
 
+//#define SK_XPS_USE_DETERMINISTIC_IDS
+
 /** \class SkXPSDevice
 
     The drawing context for the XPS backend.
 */
 class SkXPSDevice : public SkBitmapDevice {
 public:
     SK_API SkXPSDevice();
     SK_API virtual ~SkXPSDevice();
 
     virtual bool beginPortfolio(SkWStream* outputStream);
@@ skipping 126 matching lines @@
     SkTScopedComPtr<IXpsOMPackageWriter> fPackageWriter;
 
     unsigned int fCurrentPage;
     SkTScopedComPtr<IXpsOMCanvas> fCurrentXpsCanvas;
     SkSize fCurrentCanvasSize;
     SkVector fCurrentUnitsPerMeter;
     SkVector fCurrentPixelsPerMeter;
 
     SkTArray<TypefaceUse, true> fTypefaces;
 
+    /** Creates a GUID based id and places it into buffer.
+        buffer should have space for at least GUID_ID_LEN wide characters.
+        The string will always be wchar null terminated.
+        XXXXXXXXsXXXXsXXXXsXXXXsXXXXXXXXXXXX0
+        The string may begin with a digit,
+        and so may not be suitable as a bare resource key.
+     */
+    HRESULT createId(wchar_t* buffer, size_t bufferSize, wchar_t sep = '-');
+#ifdef SK_XPS_USE_DETERMINISTIC_IDS
+    decltype(GUID::Data1) fNextId = 0;

[mtklein, 2014/08/22 18:23:34]

Would prefer DWORD, whatever explicitly.

+#endif
+
     HRESULT initXpsDocumentWriter(IXpsOMImageResource* image);
 
     HRESULT createXpsPage(
         const XPS_SIZE& pageSize,
         IXpsOMPage** page);
 
     HRESULT createXpsThumbnail(
         IXpsOMPage* page, const unsigned int pageNumber,
         IXpsOMImageResource** image);
 
@@ skipping 123 matching lines @@
     virtual SkBaseDevice* onCreateDevice(const SkImageInfo&, Usage) SK_OVERRIDE;
 
     // Disable the default copy and assign implementation.
     SkXPSDevice(const SkXPSDevice&);
     void operator=(const SkXPSDevice&);
 
     typedef SkBitmapDevice INHERITED;
 };
 
 #endif