cc: Do GatherPixelRefs from skia at record time

cc/resources/picture.h

Index: cc/resources/picture.h
diff --git a/cc/resources/picture.h b/cc/resources/picture.h
index a29d5afaa6438177def4ca4af6c58e7c629d0c8a..7e4a4019678b8bfc383f136d2d77e40f805104c1 100644
--- a/cc/resources/picture.h
+++ b/cc/resources/picture.h
@@ -7,11 +7,14 @@
 
 #include <list>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "cc/base/cc_export.h"
+#include "cc/base/hash_pair.h"
 #include "skia/ext/lazy_pixel_ref.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkPixelRef.h"
@@ -30,6 +33,11 @@ struct RenderingStats;
 class CC_EXPORT Picture
     : public base::RefCountedThreadSafe<Picture> {
  public:
+  typedef std::pair<int, int> PixelRefMapKey;
+  typedef base::hash_map<
+      PixelRefMapKey,
+      std::list<skia::LazyPixelRef*> > PixelRefMap;
+
   static scoped_refptr<Picture> Create(gfx::Rect layer_rect);
   static scoped_refptr<Picture> CreateFromBase64String(
       const std::string& encoded_string);
@@ -58,12 +66,31 @@ class CC_EXPORT Picture
               float contents_scale,
               bool enable_lcd_text);
 
-  void GatherPixelRefs(
-      const gfx::Rect& layer_rect,
-      std::list<skia::LazyPixelRef*>& pixel_ref_list);
-
   void AsBase64String(std::string* output) const;
 
+  class CC_EXPORT LazyPixelRefIterator {

[reveman, 2013/04/23 14:33:24]

Seem to be some inconsistency in when the term "lazy" is used. Some variables
use it but others don't. I would prefer to use PixelRefIterator and remove usage
of term lazy everywhere except skia::LazyPixelRef of course. Wdyt?

[vmpstr, 2013/04/23 20:02:23]

Agreed. I renamed it.

+   public:
+    LazyPixelRefIterator();
+    LazyPixelRefIterator(gfx::Rect layer_rect, const Picture* picture);
+    ~LazyPixelRefIterator();
+
+    skia::LazyPixelRef* operator->() const { return current_pixel_ref_; }
+    skia::LazyPixelRef* operator*() const { return current_pixel_ref_; }
+    LazyPixelRefIterator& operator++();
+    operator bool() const { return !!current_pixel_ref_; }
+
+   private:
+    const Picture* picture_;
+    const std::list<skia::LazyPixelRef*>* current_list_;
+    std::list<skia::LazyPixelRef*>::const_iterator current_list_iterator_;
+    skia::LazyPixelRef* current_pixel_ref_;
+
+    gfx::Point min_point_;
+    gfx::Point max_point_;
+    int current_x_;
+    int current_y_;
+  };
+
  private:
   explicit Picture(gfx::Rect layer_rect);
   Picture(const std::string& encoded_string, bool* success);
@@ -71,9 +98,15 @@ class CC_EXPORT Picture
   // ownership to this picture.
   Picture(const skia::RefPtr<SkPicture>&,
           gfx::Rect layer_rect,
-          gfx::Rect opaque_rect);
+          gfx::Rect opaque_rect,
+          const PixelRefMap& lazy_pixel_refs);
   ~Picture();
 
+  void GatherPixelRefsFromSkia(
+      const gfx::Rect& query_rect,
+      std::list<skia::LazyPixelRef*>& pixel_ref_list);
+  void GatherAllPixelRefs();
+
   gfx::Rect layer_rect_;
   gfx::Rect opaque_rect_;
   skia::RefPtr<SkPicture> picture_;
@@ -81,7 +114,13 @@ class CC_EXPORT Picture
   typedef std::vector<scoped_refptr<Picture> > PictureVector;
   PictureVector clones_;
 
+  PixelRefMap lazy_pixel_refs_;
+  gfx::Point min_lazy_pixel_cell_;
+  gfx::Point max_lazy_pixel_cell_;
+  gfx::Size cell_size_;
+
   friend class base::RefCountedThreadSafe<Picture>;
+  friend class LazyPixelRefIterator;
   DISALLOW_COPY_AND_ASSIGN(Picture);
 };