cc: Moving anti-aliasing decision to parent compositor.

cc/draw_quad.h

Index: cc/draw_quad.h
diff --git a/cc/draw_quad.h b/cc/draw_quad.h
index df62c7b05bae5f0591746fe4de83aa2815a93b81..d6b9b40df150fba060627bf63622e89ef9b221ee 100644
--- a/cc/draw_quad.h
+++ b/cc/draw_quad.h
@@ -67,6 +67,7 @@ class CC_EXPORT DrawQuad {
   const SharedQuadState* shared_quad_state;
 
   bool IsDebugQuad() const { return material == DEBUG_BORDER; }
+
   bool ShouldDrawWithBlending() const {
     return needs_blending || shared_quad_state->opacity < 1.0f ||
         !opaque_rect.Contains(visible_rect);
@@ -76,6 +77,32 @@ class CC_EXPORT DrawQuad {
       ResourceProvider::ResourceId)> ResourceIteratorCallback;
   virtual void IterateResources(const ResourceIteratorCallback& callback) = 0;
 
+  // Is the left edge of this tile aligned with the originating layer's
+  // left edge?
+  bool IsLeftEdge() const { return !rect.x(); }
+
+  // Is the top edge of this tile aligned with the originating layer's
+  // top edge?
+  bool IsTopEdge() const { return !rect.y(); }
+
+  // Is the right edge of this tile aligned with the originating layer's
+  // right edge?
+  bool IsRightEdge() const {
+    return rect.right() == shared_quad_state->content_bounds.width();
+  }
+
+  // Is the bottom edge of this tile aligned with the originating layer's
+  // bottom edge?
+  bool IsBottomEdge() const {
+    return rect.bottom() == shared_quad_state->content_bounds.height();
+  }
+
+  // Is any edge of this tile aligned with the originating layer's
+  // corresponding edge?
+  bool IsEdge() const {
+    return IsLeftEdge() || IsTopEdge() || IsRightEdge() || IsBottomEdge();
+  }
+
  protected:
   DrawQuad();