Improve ergonomics of CanvasImageSource -> gfx::ImageSkia.

ui/gfx/image/canvas_image_source.h

Index: ui/gfx/image/canvas_image_source.h
diff --git a/ui/gfx/image/canvas_image_source.h b/ui/gfx/image/canvas_image_source.h
index f41c2814c0a81a59b86cf07da949a5b0d0c80284..55cb7a6c286219a5d595001524de95e33179b4b4 100644
--- a/ui/gfx/image/canvas_image_source.h
+++ b/ui/gfx/image/canvas_image_source.h
@@ -7,8 +7,10 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/gfx_export.h"
+#include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_source.h"
 
 namespace gfx {
@@ -21,6 +23,15 @@ class ImageSkiaRep;
 // completed.
 class GFX_EXPORT CanvasImageSource : public gfx::ImageSkiaSource {
  public:
+  template <typename T, typename... Args>

[Robert Sesek, 2016/09/26 21:59:53]

Should have a comment here.

[Evan Stade, 2016/09/28 01:52:34]

Done.

+  static ImageSkia MakeImageSkia(Args&&... args) {
+    auto source = base::MakeUnique<T>(std::forward<Args>(args)...);
+    gfx::Size size = source->size();

[oshima, 2016/09/27 22:50:26]

why not just do this inline below?

 

[Evan Stade, 2016/09/28 01:52:34]

source.release() invalidates source and we don't know what order the arguments
will be evaluated in.

+    return gfx::ImageSkia(source.release(), size);
+  }
+
+  ~CanvasImageSource() override {}

[Robert Sesek, 2016/09/26 21:59:53]

Place the dtor after the ctor.

[Evan Stade, 2016/09/28 01:52:34]

Done.

+
   CanvasImageSource(const gfx::Size& size, bool is_opaque);
 
   // Called when a new image needs to be drawn for a scale factor.
@@ -33,8 +44,6 @@ class GFX_EXPORT CanvasImageSource : public gfx::ImageSkiaSource {
   gfx::ImageSkiaRep GetImageForScale(float scale) override;
 
  protected:
-  ~CanvasImageSource() override {}
-
   const gfx::Size size_;
   const bool is_opaque_;
   DISALLOW_COPY_AND_ASSIGN(CanvasImageSource);