feat(button): adds attribute override for ripple size

Closes #1088.

src/components/button/button.js

@@ -32,6 +32,7 @@ angular.module('material.components.button', [
  *
  * @param {boolean=} md-no-ink If present, disable ripple ink effects.
  * @param {expression=} ng-disabled En/Disable based on the expression
+ * @param {string=} md-ripple-size Overrides the default ripple size logic. Options: `full`, `partial`, `auto`
  * @param {string=} aria-label Adds alternative text to button for accessibility, useful for icon buttons.
  * If no default text is found, a warning will be logged.
  *

src/core/services/ripple/ripple.js

@@ -79,8 +79,18 @@ function InkRippleService($window, $timeout) {
         isActive = false,
         isHeld = false,
         node = element[0],
+        rippleSizeSetting = element.attr('md-ripple-size'),
         color = parseColor(element.attr('md-ink-ripple')) || parseColor($window.getComputedStyle(options.colorElement[0]).color || 'rgb(0, 0, 0)');
 
+    switch (rippleSizeSetting) {
+      case 'full':
+        options.isFAB = true;
+        break;
+      case 'partial':
+        options.isFAB = false;
+        break;
+    }
+
     // expose onInput for ripple testing
     if (options.mousedown) {
       element.on('$md.pressdown', onPressDown)
@@ -272,7 +282,7 @@ function InkRippleService($window, $timeout) {
           size = 2 * Math.sqrt(Math.pow(width, 2) + Math.pow(height, 2));
         } else {
           multiplier = options.isFAB ? 1.1 : 0.8;
-          size = Math.max(width, height) * multiplier;
+          size = Math.sqrt(Math.pow(width, 2) + Math.pow(height, 2)) * multiplier;
         }
         return size;
       }