[cc] Initial checkin of cc-frame-viewer

tools/cc-frame-viewer/src/model/layer_tree_impl.js

+/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+'use strict';
+
+base.require('base.bbox2');
+base.require('model.constants');
+
+base.exportTo('ccfv.model', function() {
+
+  /**
+   * Represents a cc::LayerTreeImpl
+   *
+   * @constructor
+   */
+  function LayerTreeImpl(which_tree) {
+    this.which_tree = which_tree;
+    this.tiles = [];
+    this.tileBBox_ = undefined;
+  };
+
+  LayerTreeImpl.prototype = {
+    resetTiles: function() {
+      this.tilse = [];
+      this.tileBBox_ = undefined;
+    },
+
+    get tileBBox() {
+      if (!this.tileBBox_) {
+        var bbox = new base.BBox2();
+        for (var i = 0; i < this.tiles.length; i++) {
+          var tile = this.tiles[i];
+          var priority = tile.priority[this.which_tree];
+          if (!priority.current_screen_quad)
+            continue;
+          bbox.addQuad(priority.current_screen_quad);
+        }
+        this.tileBBox_ = bbox;
+      }
+      return this.tileBBox_;
+    },
+
+  };
+
+  return {
+    LayerTreeImpl: LayerTreeImpl
+  }
+});
+