Add SkImageGeneratorWIC

src/ports/SkImageGeneratorWIC.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-#include "SkTypes.h"
-#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
-
-#include "SkCGUtils.h"
 #include "SkData.h"
 #include "SkImageGenerator.h"
 #include "SkTemplates.h"
+#include "SkTScopedComPtr.h"
+#include "SkTypes.h"
 
-class SkImageGeneratorCG : public SkImageGenerator {
+#include <wincodec.h>
+
+/*
+ * Requires that the client has initialized COM on the calling thread.

[scroggo, 2016/03/17 17:05:59]

nit: So every thread that uses this needs to have initialized COM? e.g. Call
NewFromEncodedWIC on the main thread, then call getPixels from a thread spun up
for decoding. Both need to have initialized COM? Should this comment be more
specific about what it means by "the calling thread"?

[msarett, 2016/03/17 17:32:35]

Yes, I've tried to make this clearer.

+ */
+class SkImageGeneratorWIC : public SkImageGenerator {
 public:
     /*
      * Refs the data if an image generator can be returned.  Otherwise does
      * not affect the data.
      */
-    static SkImageGenerator* NewFromEncodedCG(SkData* data);
+    static SkImageGenerator* NewFromEncodedWIC(SkData* data);
 
 protected:
     SkData* onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) override;
 
     bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, SkPMColor ctable[],
             int* ctableCount) override;
 
 private:
     /*
-     * Takes ownership of the imageSrc
+     * Takes ownership of the imagingFactory
+     * Takes ownership of the imageSource
      * Refs the data
      */
-    SkImageGeneratorCG(const SkImageInfo& info, const void* imageSrc, SkData* data);
+    SkImageGeneratorWIC(const SkImageInfo& info, IWICImagingFactory* imagingFactory,
+            IWICBitmapSource* imageSource, SkData* data);
 
-    SkAutoTCallVProc<const void, CFRelease> fImageSrc;
-    SkAutoTUnref<SkData>                    fData;
+    SkTScopedComPtr<IWICImagingFactory> fImagingFactory;
+    SkTScopedComPtr<IWICBitmapSource>   fImageSource;
+    SkAutoTUnref<SkData>                fData;
     
     typedef SkImageGenerator INHERITED;
 };
-
-#endif //defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)