[NOT FOR COMMIT] Fully replace SkCanvas uses.

cc/playback/discardable_image_map.h

Index: cc/playback/discardable_image_map.h
diff --git a/cc/playback/discardable_image_map.h b/cc/playback/discardable_image_map.h
index 00506809a5fcba8869307187813fbd9bd8a72a4a..ecb245a81831ffc6eb9dfab61396fd7d4f70a93e 100644
--- a/cc/playback/discardable_image_map.h
+++ b/cc/playback/discardable_image_map.h
@@ -11,7 +11,7 @@
 #include "cc/base/cc_export.h"
 #include "cc/base/rtree.h"
 #include "cc/playback/draw_image.h"
-#include "third_party/skia/include/core/SkCanvas.h"
+#include "skia/ext/cdl_paint.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
@@ -32,11 +32,12 @@ class CC_EXPORT DiscardableImageMap {
                             const gfx::Size& bounds);
     ~ScopedMetadataGenerator();
 
-    SkCanvas* canvas() { return metadata_canvas_.get(); }
+    CdlCanvas* canvas() { return metadata_canvas_.get(); }
 
    private:
     DiscardableImageMap* image_map_;
-    std::unique_ptr<SkCanvas> metadata_canvas_;
+    // TODO(cdl): switch to unique_ptr.
+    std::unique_ptr<CdlCanvas> metadata_canvas_;
   };
 
   DiscardableImageMap();
@@ -51,7 +52,7 @@ class CC_EXPORT DiscardableImageMap {
   friend class ScopedMetadataGenerator;
   friend class DiscardableImageMapTest;
 
-  std::unique_ptr<SkCanvas> BeginGeneratingMetadata(const gfx::Size& bounds);
+  std::unique_ptr<CdlCanvas> BeginGeneratingMetadata(const gfx::Size& bounds);
   void EndGeneratingMetadata();
 
   std::vector<std::pair<DrawImage, gfx::Rect>> all_images_;