move skpdiff into tools

experimental/skpdiff/diff_viewer.js

-angular.module('diff_viewer', []).
-config(['$routeProvider', function($routeProvider) {
-    // Show the list of differences by default
-    $routeProvider.
-    otherwise({ templateUrl: '/diff_list.html', controller: DiffListController});
-}]).
-directive('swapImg', function() {
-    // Custom directive for showing an image that gets swapped my mouseover.
-    return {
-        restrict: 'E', // The directive can be used as an element name
-        replace: true, // The directive replaces itself with the template
-        template: '<canvas ng-mouseenter="swap()" ng-mouseleave="swap()"></canvas>',
-        scope: { // The attributes below are bound to the scope
-            leftSrc: '@',
-            rightSrc: '@',
-            side: '@'
-        },
-        link: function(scope, elm, attrs, ctrl) {
-            var leftImage = new Image();
-            var rightImage = new Image();
-            var ctx = elm[0].getContext('2d');
-
-            scope.render = function() {
-                var image;
-                if (scope.side == "left") {
-                    image = leftImage;
-                } else {
-                    image = rightImage;
-                }
-
-                // Make it so the maximum size of an image is 500, and the images are scaled
-                // down in halves.
-                var divisor = 1;
-                while ((image.width / divisor) > 500) {
-                    divisor *= 2;
-                }
-
-                // Set canvas to correct size and draw the image into it
-                elm[0].width = image.width / divisor;
-                elm[0].height = image.height / divisor;
-                ctx.drawImage(image, 0, 0, elm[0].width, elm[0].height);
-            };
-
-            // When the leftSrc attribute changes, load the image and then rerender
-            attrs.$observe('leftSrc', function(value) {
-                leftImage.src = value;
-                leftImage.onload = function() {
-                    if (scope.side == "left") {
-                        scope.render();
-                    }
-                };
-            });
-
-            // When the rightSrc attribute changes, load the image and then rerender
-            attrs.$observe('rightSrc', function(value) {
-                rightImage.src = value;
-                rightImage.onload = function() {
-                    if (scope.side == "right") {
-                        scope.render();
-                    }
-                };
-            });
-
-            // Swap which side to draw onto the canvas and then rerender
-            scope.swap = function() {
-                if (scope.side == "left") {
-                    scope.side = "right";
-                } else {
-                    scope.side = "left";
-                }
-                scope.render();
-            };
-        }
-    };
-});
-
-function DiffListController($scope) {
-    // Label each kind of differ for the sort buttons.
-    $scope.differs = [
-        {
-            "title": "Different Pixels"
-        },
-        {
-            "title": "Perceptual Difference"
-        }
-    ];
-
-    // Puts the records within AngularJS scope
-    $scope.records = SkPDiffRecords.records;
-
-    // Indicates which diff metric is used for sorting
-    $scope.sortIndex = 1;
-
-    // Called by the sort buttons to adjust the metric used for sorting
-    $scope.setSortIndex = function(idx) {
-        $scope.sortIndex = idx;
-    };
-
-    // A predicate for pulling out the number used for sorting
-    $scope.sortingDiffer = function(record) {
-        return record.diffs[$scope.sortIndex].result;
-    };
-}