JPEG decoding: replace ownership comments with std::unique_ptr.

components/suggestions/image_encoder.cc

Index: components/suggestions/image_encoder.cc
diff --git a/components/suggestions/image_encoder.cc b/components/suggestions/image_encoder.cc
index 5e92b653a58e6a613e8785b2e6dc973cba7e1104..73283cf5bbbd694cdc5e8eacc9060841f87cc129 100644
--- a/components/suggestions/image_encoder.cc
+++ b/components/suggestions/image_encoder.cc
@@ -9,7 +9,8 @@
 
 namespace suggestions {
 
-SkBitmap* DecodeJPEGToSkBitmap(const void* encoded_data, size_t size) {
+std::unique_ptr<SkBitmap> DecodeJPEGToSkBitmap(const void* encoded_data,
+                                               size_t size) {
   return gfx::JPEGCodec::Decode(static_cast<const unsigned char*>(encoded_data),
                                 size);
 }