Make NavigateFrameToURL return a success value like NavigateToURL.

This is just a convenience. I've simplified one use of this. I'll be
adding another use in a different CL.

https://crrev.com/c/2148914 wraps all calls to this in EXPECT_TRUE but
of course there are failures. It would be a bad idea to submit this
right now with the code-freeze anyway. So I'll come back to it.

Change-Id: I16b170fe8e697d0eb06716e30b877efdaa523869
Bug: 1071297
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2148711
Commit-Queue: Fergal Daly <fergal@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759519}

content/browser/find_request_manager_browsertest.cc

@@ -83,10 +83,7 @@ class FindRequestManagerTest : public ContentBrowserTest,
     GURL url(embedded_test_server()->GetURL(
         "b.com", child->current_url().path()));
 
-    TestNavigationObserver observer(shell()->web_contents());
-    NavigateFrameToURL(child, url);
-    EXPECT_EQ(url, observer.last_navigation_url());
-    EXPECT_TRUE(observer.last_navigation_succeeded());
+    EXPECT_TRUE(NavigateFrameToURL(child, url));
   }
 
   void Find(const std::string& search_text,

content/test/content_browser_test_utils_internal.cc

@@ -45,13 +45,24 @@
 
 namespace content {
 
-void NavigateFrameToURL(FrameTreeNode* node, const GURL& url) {
+bool NavigateFrameToURL(FrameTreeNode* node, const GURL& url) {
   TestFrameNavigationObserver observer(node);
   NavigationController::LoadURLParams params(url);
   params.transition_type = ui::PAGE_TRANSITION_LINK;
   params.frame_tree_node_id = node->frame_tree_node_id();
   node->navigator()->GetController()->LoadURLWithParams(params);
   observer.Wait();
+
+  if (!observer.last_navigation_succeeded()) {
+    DLOG(WARNING) << "Navigation did not succeed: " << url;
+    return false;
+  }
+  if (url != node->current_url()) {
+    DLOG(WARNING) << "Expected URL " << url << " but observed "
+                  << node->current_url();
+    return false;
+  }
+  return true;
 }
 
 void SetShouldProceedOnBeforeUnload(Shell* shell, bool proceed, bool success) {

content/test/content_browser_test_utils_internal.h

@@ -39,8 +39,9 @@ class SiteInstance;
 class ToRenderFrameHost;
 
 // Navigates the frame represented by |node| to |url|, blocking until the
-// navigation finishes.
-void NavigateFrameToURL(FrameTreeNode* node, const GURL& url);
+// navigation finishes. Returns true if the navigation succeedd and the final
+// URL matches |url|.
+bool NavigateFrameToURL(FrameTreeNode* node, const GURL& url);
 
 // Sets the DialogManager to proceed by default or not when showing a
 // BeforeUnload dialog, and if it proceeds, what value to return.