core(driver): guard verbose logic behind log.isVerbose check (#14086)

lighthouse-core/gather/driver/wait-for-condition.js

@@ -164,7 +164,8 @@ function waitForNetworkIdle(session, networkMonitor, networkQuietOptions) {
       const inflightRecords = networkMonitor.getInflightRequests();
       // If there are more than 20 inflight requests, load is still in full swing.
       // Wait until it calms down a bit to be a little less spammy.
-      if (inflightRecords.length < 20) {
+      if (log.isVerbose() && inflightRecords.length < 20 && inflightRecords.length > 0) {
+        log.verbose('waitFor', `=== Waiting on ${inflightRecords.length} requests to finish`);
         for (const record of inflightRecords) {
           log.verbose('waitFor', `Waiting on ${record.url.slice(0, 120)} to finish`);
         }

types/lighthouse-logger/index.d.ts

@@ -11,6 +11,7 @@ declare module 'lighthouse-logger' {
     args?: any[];
   }
   export function setLevel(level: string): void;
+  export function isVerbose(): boolean;
   export function formatProtocol(prefix: string, data: Object, level?: string): void;
   export function log(title: string, ...args: any[]): void;
   export function warn(title: string, ...args: any[]): void;