Support optional performance measuring in SubresourceFilter.

components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc

Index: components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc
diff --git a/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc b/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc
index abd8a140db35609bb3d0e67a9db36f8e3884801c..e7b47a523771fc1aa624353330e4402bf89600ce 100644
--- a/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc
+++ b/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.cc
@@ -122,8 +122,14 @@ void ContentSubresourceFilterDriverFactory::ActivateForFrameHostIfNeeded(
     content::RenderFrameHost* render_frame_host,
     const GURL& url) {
   if (activation_state_ != ActivationState::DISABLED) {
-    DriverFromFrameHost(render_frame_host)
-        ->ActivateForProvisionalLoad(GetMaximumActivationState(), url);
+    // TODO(pkalinnikov): Introduce a variation parameter controlling how often
+    // the |measure_performance| bit is set. crbug/672519
+    constexpr bool measure_performance = true;
+
+    auto* driver = DriverFromFrameHost(render_frame_host);
+    DCHECK(driver);
+    driver->ActivateForProvisionalLoad(GetMaximumActivationState(), url,
+                                       measure_performance);
   }
 }