Make selection solid and blue in Files.app.

chrome/browser/resources/file_manager/js/file_table.js

Index: chrome/browser/resources/file_manager/js/file_table.js
diff --git a/chrome/browser/resources/file_manager/js/file_table.js b/chrome/browser/resources/file_manager/js/file_table.js
index 566be9b21a2a221c779e8cfdd0bab6d998b45cac..dd1f04c1d535647177dffaa6ecc2e61882463572 100644
--- a/chrome/browser/resources/file_manager/js/file_table.js
+++ b/chrome/browser/resources/file_manager/js/file_table.js
@@ -148,8 +148,14 @@ FileTable.decorate = function(self, metadataCache, fullPage) {
   self.setRenderFunction(self.renderTableRow_.bind(self,
       self.getRenderFunction()));
 
-  if (util.platform.newUI())
+  if (util.platform.newUI()) {
     ScrollBar.createVertical(self, self.list);
+    // Keep focus on the file list when clicking on the header.
+    self.header.addEventListener('mousedown', function(e) {
+      self.list.focus();
+      e.preventDefault();
+    });
+  }
 
   var handleSelectionChange = function() {
     var selectAll = self.querySelector('#select-all-checkbox');