cc: Use gather pixel refs with positions util.

cc/resources/picture.cc

Index: cc/resources/picture.cc
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index b0f3fa30e59f0587759f402efd64fd6fe71392da..4fd99b9cb19df9de7ebbfc06bce0e8dd890100e5 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -17,7 +17,7 @@
 #include "cc/debug/traced_picture.h"
 #include "cc/debug/traced_value.h"
 #include "cc/layers/content_layer_client.h"
-#include "skia/ext/analysis_canvas.h"
+#include "skia/ext/lazy_pixel_ref_utils.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkDrawFilter.h"
@@ -92,37 +92,6 @@ class DisableLCDTextFilter : public SkDrawFilter {
   }
 };
 
-// URI label for a lazily decoded SkPixelRef.
-const char kLabelLazyDecoded[] = "lazy";
-
-void GatherPixelRefsForRect(
-    SkPicture* picture,
-    gfx::Rect rect,
-    Picture::PixelRefs* pixel_refs) {
-  DCHECK(picture);
-  SkData* pixel_ref_data = SkPictureUtils::GatherPixelRefs(
-      picture,
-      gfx::RectToSkRect(rect));
-  if (!pixel_ref_data)
-    return;
-
-  void* data = const_cast<void*>(pixel_ref_data->data());
-  if (!data) {
-    pixel_ref_data->unref();
-    return;
-  }
-
-  SkPixelRef** refs = reinterpret_cast<SkPixelRef**>(data);
-  for (size_t i = 0; i < pixel_ref_data->size() / sizeof(*refs); ++i) {
-    if (*refs && (*refs)->getURI() &&
-        !strncmp((*refs)->getURI(), kLabelLazyDecoded, 4)) {
-      pixel_refs->push_back(static_cast<skia::LazyPixelRef*>(*refs));
-    }
-    refs++;
-  }
-  pixel_ref_data->unref();
-}
-
 }  // namespace
 
 scoped_refptr<Picture> Picture::Create(gfx::Rect layer_rect) {
@@ -302,29 +271,33 @@ void Picture::GatherPixelRefs(
   if (stats)
     begin_image_gathering_time = base::TimeTicks::Now();
 
-  gfx::Size layer_size(layer_rect_.size());
-
-  // Capture pixel refs for this picture in a grid
-  // with cell_size_ sized cells.
-  pixel_refs_.clear();
-  for (int y = 0; y < layer_rect_.height(); y += cell_size_.height()) {
-    for (int x = 0; x < layer_rect_.width(); x += cell_size_.width()) {
-      gfx::Rect rect(gfx::Point(x, y), cell_size_);
-      rect.Intersect(gfx::Rect(gfx::Point(), layer_rect_.size()));
-
-      PixelRefs pixel_refs;
-      GatherPixelRefsForRect(picture_.get(), rect, &pixel_refs);
-
-      // Only capture non-empty cells.
-      if (!pixel_refs.empty()) {
+  skia::LazyPixelRefList pixel_refs;
+  skia::LazyPixelRefUtils::GatherPixelRefs(picture_.get(), &pixel_refs);
+  for (skia::LazyPixelRefList::const_iterator it = pixel_refs.begin();
+       it != pixel_refs.end();
+       ++it) {
+    gfx::Point min(
+        RoundDown(static_cast<int>(it->pixel_ref_rect.x()),
+                  cell_size_.width()),
+        RoundDown(static_cast<int>(it->pixel_ref_rect.y()),
+                  cell_size_.height()));
+    gfx::Point max(
+        RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.right())),
+                  cell_size_.width()),
+        RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.bottom())),
+                  cell_size_.height()));
+
+    for (int y = min.y(); y <= max.y(); y += cell_size_.height()) {
+      for (int x = min.x(); x <= max.x(); x += cell_size_.width()) {
         PixelRefMapKey key(x, y);
-        pixel_refs_[key].swap(pixel_refs);
-        min_x = std::min(min_x, x);
-        min_y = std::min(min_y, y);
-        max_x = std::max(max_x, x);
-        max_y = std::max(max_y, y);
+        pixel_refs_[key].push_back(it->lazy_pixel_ref);
       }
     }
+
+    min_x = std::min(min_x, min.x());
+    min_y = std::min(min_y, min.y());
+    max_x = std::max(max_x, max.x());
+    max_y = std::max(max_y, max.y());
   }
 
   if (stats) {