Convert tests to use the non-deprecated WebContentsObserver navigation methods.

chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc

Index: chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
diff --git a/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc b/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
index feec62e949c3f7171f3eceac3116a17bce05b55b..eea35bf5c924c06f0a235e7a6965a008412c77bc 100644
--- a/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
+++ b/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
@@ -266,11 +266,9 @@ class StartProvisionalLoadObserver : public content::WebContentsObserver {
         message_loop_runner_(new content::MessageLoopRunner) {}
   ~StartProvisionalLoadObserver() override {}
 
-  void DidStartProvisionalLoadForFrame(
-      content::RenderFrameHost* render_frame_host,
-      const GURL& validated_url,
-      bool is_error_page) override {
-    if (validated_url == url_) {
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override {
+    if (navigation_handle->GetURL() == url_) {
       url_seen_ = true;
       message_loop_runner_->Quit();
     }