Cleanup Tool WebUI: Add functionality to the Scan button

chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js

Index: chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js
diff --git a/chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js b/chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js
index 1e0e859e4b569d28bdba3d474d875521961b1470..d62dbe2f3f9bce7da044e83031bb4261576e769f 100644
--- a/chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js
+++ b/chrome/browser/resources/cleanup_tool/cleanup_browser_proxy.js
@@ -27,6 +27,11 @@ cr.define('cleanup', function() {
      * @return {!Promise<LastScanResult>}
      */
     requestLastScanResult: function() {},
+    /**
+     * Attempts to run the Chrome Cleanup Tool in scanning mode.
+     * @return {!Promise<LastScanResult>}
+     */
+    startScan: function() {},
   };
 
   /**
@@ -41,6 +46,10 @@ cr.define('cleanup', function() {
     requestLastScanResult: function() {
       return cr.sendWithPromise('requestLastScanResult');
     },
+    /** @override */
+    startScan: function() {
+      return cr.sendWithPromise('startScan');
+    },
   };
 
   return {