Introduces ImageSkia::GetRepresentations() for Mac

ui/gfx/image/image_skia.cc

Index: ui/gfx/image/image_skia.cc
diff --git a/ui/gfx/image/image_skia.cc b/ui/gfx/image/image_skia.cc
index 9472cda8b6be4d26c4bc42e63e0a893e4536ff34..7dd1e78fe0420294ad516880bf1ef583f7742a54 100644
--- a/ui/gfx/image/image_skia.cc
+++ b/ui/gfx/image/image_skia.cc
@@ -53,6 +53,8 @@ class ImageSkiaStorage : public base::RefCounted<ImageSkiaStorage> {
         size_(size) {
   }
 
+  bool has_source() const { return source_.get() != NULL; }
+
   std::vector<gfx::ImageSkiaRep>& image_reps() { return image_reps_; }
 
   const gfx::Size& size() const { return size_; }
@@ -191,7 +193,7 @@ void ImageSkia::RemoveRepresentation(ui::ScaleFactor scale_factor) {
     image_reps.erase(it);
 }
 
-bool ImageSkia::HasRepresentation(ui::ScaleFactor scale_factor) {
+bool ImageSkia::HasRepresentation(ui::ScaleFactor scale_factor) const {
   if (isNull())
     return false;
 
@@ -213,6 +215,36 @@ const ImageSkiaRep& ImageSkia::GetRepresentation(
   return *it;
 }
 
+std::vector<ImageSkiaRep> ImageSkia::GetRepresentations() const {
+  if (isNull())
+    return std::vector<ImageSkiaRep>();
+
+  if (!storage_->has_source())
+    return image_reps();
+
+  // Attempt to generate image reps for as many scale factors supported by
+  // this platform as possible.
+  // Do not build return array here because the mapping from scale factor to
+  // image rep is one to many in some cases.
+  std::vector<ui::ScaleFactor> supported_scale_factors =
+      ui::GetSupportedScaleFactors();
+  for (size_t i = 0; i < supported_scale_factors.size(); ++i) {
+    storage_->FindRepresentation(supported_scale_factors[i], true);
+  }
+
+  ImageSkiaReps internal_image_reps = storage_->image_reps();
+  // Create list of image reps to return, skipping null image reps which were
+  // added for caching purposes only.
+  ImageSkiaReps image_reps;
+  for (ImageSkiaReps::iterator it = internal_image_reps.begin();
+       it != internal_image_reps.end(); ++it) {
+    if (!it->is_null())
+      image_reps.push_back(*it);
+  }
+
+  return image_reps;
+}
+
 bool ImageSkia::empty() const {
   return isNull() || storage_->size().IsEmpty();
 }
@@ -270,7 +302,9 @@ const SkBitmap* ImageSkia::bitmap() const {
     return &NullImageRep().sk_bitmap();
   }
 
-  return &storage_->image_reps()[0].sk_bitmap();
+  ImageSkiaReps::iterator it =
+      storage_->FindRepresentation(ui::SCALE_FACTOR_100P, true);
+  return &it->sk_bitmap();
 }
 
 void ImageSkia::Init(const ImageSkiaRep& image_rep) {