Remove unneeded files from third_party/polymer.

third_party/polymer/v1_0/components-chromium/paper-dialog-behavior/.bower.json

-{
-  "name": "paper-dialog-behavior",
-  "version": "1.2.0",
-  "description": "Implements a behavior used for material design dialogs",
-  "authors": "The Polymer Authors",
-  "keywords": [
-    "web-components",
-    "polymer",
-    "dialog",
-    "overlay",
-    "behavior"
-  ],
-  "main": "paper-dialog-behavior.html",
-  "private": true,
-  "repository": {
-    "type": "git",
-    "url": "git://github.com/PolymerElements/paper-dialog-behavior"
-  },
-  "license": "http://polymer.github.io/LICENSE.txt",
-  "homepage": "https://github.com/PolymerElements/paper-dialog-behavior",
-  "ignore": [],
-  "dependencies": {
-    "iron-overlay-behavior": "PolymerElements/iron-overlay-behavior#^1.0.0",
-    "paper-styles": "PolymerElements/paper-styles#^1.1.0",
-    "polymer": "Polymer/polymer#^1.1.0"
-  },
-  "devDependencies": {
-    "iron-component-page": "PolymerElements/iron-component-page#^1.0.0",
-    "iron-demo-helpers": "PolymerElements/iron-demo-helpers#^1.0.0",
-    "iron-test-helpers": "PolymerElements/iron-test-helpers#^1.0.0",
-    "paper-button": "PolymerElements/paper-button#^1.0.0",
-    "paper-dialog-scrollable": "PolymerElements/paper-dialog-scrollable#^1.0.0",
-    "paper-icon-button": "PolymerElements/paper-icon-button#^1.0.0",
-    "web-component-tester": "^4.0.0",
-    "webcomponentsjs": "webcomponents/webcomponentsjs#^0.7.0"
-  },
-  "_release": "1.2.0",
-  "_resolution": {
-    "type": "version",
-    "tag": "v1.2.0",
-    "commit": "a3be07d2784073d5e9e5175fb7d13f7b1f2a5558"
-  },
-  "_source": "git://github.com/PolymerElements/paper-dialog-behavior.git",
-  "_target": "^1.0.0",
-  "_originalSource": "PolymerElements/paper-dialog-behavior"
-}