Update bower.json for Polymer elements and add PRESUBMIT.py

third_party/polymer/v1_0/components/paper-slider/README.md

 paper-slider
 ============
 
 `paper-slider` allows user to select a value from a range of values by
 moving the slider thumb.  The interactive nature of the slider makes it a
 great choice for settings that reflect intensity levels, such as volume,
 brightness, or color saturation.
 
 Example:
 
 ```html
 <paper-slider></paper-slider>
 ```
 
 Use `min` and `max` to specify the slider range. Default is `0` to `100`. For example:
 ```html
 <paper-slider min="10" max="200" value="110"></paper-slider>
 ```
 
 ### Styling slider
 
-To change the slider progress bar color:
-```css
+The following custom properties and mixins are available for styling:
+
+Custom property | Description | Default
+----------------|-------------|----------
+`--paper-slider-bar-color` | The background color of the slider | `transparent`
+`--paper-slider-active-color` | The progress bar color | `--google-blue-700`
+`--paper-slider-secondary-color` | The secondary progress bar color | `--google-blue-300`
+`--paper-slider-knob-color` | The knob color | `--google-blue-700`
+`--paper-slider-disabled-knob-color` | The disabled knob color | `--google-grey-500`
+`--paper-slider-pin-color` | The pin color | `--google-blue-700`
+`--paper-slider-font-color` | The pin's text color | `#fff`
+`--paper-slider-disabled-active-color` | The disabled progress bar color | `--google-grey-500`
+`--paper-slider-disabled-secondary-color` | The disabled secondary progress bar color | `--google-grey-300`
+
+Example:
+
+```
 paper-slider {
+  --paper-slider-bar-color: #fff;
   --paper-slider-active-color: #0f9d58;
+  --paper-slider-knob-color: #0f9d58;
+  --paper-slider-pin-color: #0f9d58;
+  --paper-slider-font-color: #0f9d58;
+  --paper-slider-secondary-color: #0f9d58;
+  --paper-slider-disabled-active-color: #ccc;
+  --paper-slider-disabled-secondary-color: #ccc;
 }
 ```
-
-To change the slider knob color:
-```css
-paper-slider {
-  --paper-slider-knob-color: #0f9d58;
-}
-```
-
-To change the slider pin color:
-```css
-paper-slider {
-  --paper-slider-pin-color: #0f9d58;
-}
-```
-
-To change the slider pin's font color:
-```css
-paper-slider {
-  --paper-slider-pin-font-color: #0f9d58;
-}
-```
-
-To change the slider secondary progress bar color:
-```css
-paper-slider {
-  --paper-slider-secondary-color: #0f9d58;
-}
-```
-
-To change the slider disabled active color:
-```css
-paper-slider {
-  --paper-slider-disabled-active-color: #ccc;
-}
-```
-
-To change the slider disabled secondary progress bar color:
-```css
-paper-slider {
-  --paper-slider-disabled-secondary-color: #ccc;
-}
-```