Add Snackbar hide method

Author: joaofnds

src/snackbar/snackbar.js

@@ -38,6 +38,7 @@
     this.actionHandler_ = undefined;
     this.message_ = undefined;
     this.actionText_ = undefined;
+    this.timeoutID_ = undefined;
     this.queuedNotifications_ = [];
     this.setActionHidden_(true);
   };
@@ -86,7 +87,7 @@
     this.textElement_.textContent = this.message_;
     this.element_.classList.add(this.cssClasses_.ACTIVE);
     this.element_.setAttribute('aria-hidden', 'false');
-    setTimeout(this.cleanup_.bind(this), this.timeout_);
+    this.timeoutID_ = setTimeout(this.cleanup_.bind(this), this.timeout_);
 
   };
 
@@ -127,7 +128,21 @@
     }
   };
   MaterialSnackbar.prototype['showSnackbar'] = MaterialSnackbar.prototype.showSnackbar;
-
+  /**
+   * Hide the snackbar.
+   *
+   * @public
+   */
+  MaterialSnackbar.prototype.hideSnackbar = function() {
+    if (!this.active) {
+      return;
+    }
+    if (typeof this.timeoutID_ === 'number') {
+      clearTimeout(this.timeoutID_);
+      this.cleanup_();
+    }
+  };
+  MaterialSnackbar.prototype['hideSnackbar'] = MaterialSnackbar.prototype.hideSnackbar;
   /**
    * Check if the queue has items within it.
    * If it does, display the next entry.
@@ -158,6 +173,7 @@
       this.actionHandler_ = undefined;
       this.message_ = undefined;
       this.actionText_ = undefined;
+      this.timeoutID_ = undefined;
       this.active = false;
       this.checkQueue_();
     }.bind(this), /** @type {number} */ (this.Constant_.ANIMATION_LENGTH));