Apply page load timeout from when page starts loading

If there's an error during waitForLoad (e.g. due to chrome crash
or just brokenness) in the scenario, and then hooks also need
to run things that waitForLoad, it was getting the timeout for
each waitForLoad call.

But actually pageload timeout should just be from the time it
started loading, so subsequent (e.g. ->getCurrentUrl()) get an
almost immediate timeout rather than giving it another
30 seconds.

src/ChromePage.php

@@ -16,6 +16,8 @@ class ChromePage extends DevToolsConnection
 
     private bool $is_recovering_from_crash = false;
 
+    private ?\DateTimeImmutable $page_ready_timeout = NULL;
+
     public function __construct(
         private string $window_id,
         $url,
@@ -57,13 +59,11 @@ public function waitForLoad()
     {
         if (!$this->page_ready) {
             try {
-                // @todo: need a better way of setting the timeout expiry based on the start of pageload rather than specific call
-                $timeout = new \DateTimeImmutable('+30 seconds');
                 $this->waitFor(function () {
                     return $this->page_ready;
                 },
                     'wait-for-load',
-                    $timeout
+                    $this->page_ready_timeout
                 );
             } catch (DriverException $exception) {
                 // This could then be decorated with more detail on what we're waiting for
@@ -314,6 +314,13 @@ private function setPageReady(bool $state, string $change_trigger): void
         if (!$state) {
             // Clear the response ahead of loading a new doc
             $this->response = null;
+            // Set a timeout from when the page went "not ready" so it's not affected by multiple calls to waitForLoad
+            // e.g. after an exception during loading the page.
+            // @todo: pageload expiry time should be configurable
+            $this->page_ready_timeout = new \DateTimeImmutable('+30 seconds');
+        } else {
+            // Clear the timeout for the next load
+            $this->page_ready_timeout = NULL;
         }
         $this->logger->logPageReadyStateChange($state, $change_trigger);
         $this->page_ready = $state;