cc: Anchor quad offsets to a visible quad.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index b2373fcae8326558b47b9760dd256e075fc1ad3f..b6763a021cf4896c4cabe725f3fba4f7e46c1b93 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -280,9 +280,15 @@ void PictureLayerImpl::AppendQuads(RenderPass* render_pass,
   only_used_low_res_last_append_quads_ = true;
   gfx::Rect scaled_recorded_viewport = gfx::ScaleToEnclosingRect(
       raster_source_->RecordedViewport(), max_contents_scale);
+
+  bool have_origin = false;
+  gfx::Point quad_origin;
+  gfx::Rect visible_quad_layer_rect =
+      shared_quad_state->visible_quad_layer_rect;
+
   for (PictureLayerTilingSet::CoverageIterator iter(
-           tilings_.get(), max_contents_scale,
-           shared_quad_state->visible_quad_layer_rect, ideal_contents_scale_);
+           tilings_.get(), max_contents_scale, visible_quad_layer_rect,
+           ideal_contents_scale_);
        iter; ++iter) {
     gfx::Rect geometry_rect = iter.geometry_rect();
     gfx::Rect opaque_rect = contents_opaque() ? geometry_rect : gfx::Rect();
@@ -297,6 +303,20 @@ void PictureLayerImpl::AppendQuads(RenderPass* render_pass,
     bool has_draw_quad = false;
     if (*iter && iter->draw_info().IsReadyToDraw()) {
       const TileDrawInfo& draw_info = iter->draw_info();
+
+      if (!have_origin) {
+        have_origin = true;
+        quad_origin.SetPoint(geometry_rect.x(), geometry_rect.y());
+        shared_quad_state->quad_to_target_transform.Translate(quad_origin.x(),
+                                                              quad_origin.y());
+        shared_quad_state->visible_quad_layer_rect.Offset(-quad_origin.x(),
+                                                          -quad_origin.y());
+      }
+
+      geometry_rect.Offset(-quad_origin.x(), -quad_origin.y());
+      opaque_rect.Offset(-quad_origin.x(), -quad_origin.y());
+      visible_geometry_rect.Offset(-quad_origin.x(), -quad_origin.y());
+
       switch (draw_info.mode()) {
         case TileDrawInfo::RESOURCE_MODE: {
           gfx::RectF texture_rect = iter.texture_rect();