WIP: Browser image decoding using Mojo.

chrome/browser/image_decoder.h

Index: chrome/browser/image_decoder.h
diff --git a/chrome/browser/image_decoder.h b/chrome/browser/image_decoder.h
index 2206dd9f454ebcbfc3a29674cf41e1d42eb594ee..aa85d3d336d59958073cfc36e4ad140105e670e8 100644
--- a/chrome/browser/image_decoder.h
+++ b/chrome/browser/image_decoder.h
@@ -11,12 +11,11 @@
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/sequenced_worker_pool.h"
-#include "content/public/browser/utility_process_host_client.h"
-
-class SkBitmap;
+#include "content/common/image_decoder.mojom.h"
+#include "third_party/skia/include/core/SkBitmap.h"
 
 // Decodes an image in a sandboxed process.
-class ImageDecoder : public content::UtilityProcessHostClient {
+class ImageDecoder : public base::RefCountedThreadSafe<ImageDecoder> {
  public:
   class Delegate {
    public:
@@ -59,26 +58,48 @@ class ImageDecoder : public content::UtilityProcessHostClient {
   void set_shrink_to_fit(bool shrink_to_fit) { shrink_to_fit_ = shrink_to_fit; }
 
  private:
+  friend class base::RefCountedThreadSafe<ImageDecoder>;
   // It's a reference counted object, so destructor is private.
-  ~ImageDecoder() override;
-
-  // Overidden from UtilityProcessHostClient:
-  bool OnMessageReceived(const IPC::Message& message) override;
-
-  // IPC message handlers.
-  void OnDecodeImageSucceeded(const SkBitmap& decoded_image);
-  void OnDecodeImageFailed();
+  ~ImageDecoder();
 
   // Launches sandboxed process that will decode the image.
   void DecodeImageInSandbox(const std::vector<unsigned char>& image_data);
 
+  // Mojo RPC callback.
+  void OnDecodeImageDone(bool success, content::ImageDataPtr image);
+
   Delegate* delegate_;
   std::vector<unsigned char> image_data_;
   const ImageCodec image_codec_;
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   bool shrink_to_fit_; // if needed for IPC msg size limit
+  content::ImageDecoderPtr decoder_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDecoder);
 };
 
+// TODO(amistry): Move somewhere else.
+namespace mojo {
+template <>
+struct TypeConverter<SkBitmap, content::ImageDataPtr> {
+  static SkBitmap Convert(const content::ImageDataPtr& image) {
+    SkBitmap bitmap;
+    if (!bitmap.tryAllocPixels(SkImageInfo::Make(
+        image->width, image->height,
+        static_cast<SkColorType>(image->color_type),
+        static_cast<SkAlphaType>(image->alpha_type)))) {
+      LOG(ERROR) << "Unable to create SkBitmap";
+      return bitmap;
+    }
+    if (bitmap.getSize() != image->pixels.size()) {
+      LOG(ERROR) << "Incorrect bitmap size, expected: " << image->pixels.size()
+                 << ", actual: " << bitmap.getSize();
+      return bitmap;
+    }
+    memcpy(bitmap.getPixels(), &image->pixels[0], bitmap.getSize());
+    return bitmap;
+  }
+};
+}  // namespace mojo
+
 #endif  // CHROME_BROWSER_IMAGE_DECODER_H_