Make PageLoadMetricsObserver::OnStart return ObservePolicy

chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 12 matching lines @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
 namespace page_load_metrics {
 
 namespace {
 
 const char kDefaultTestUrl[] = "https://google.com/";
 const char kDefaultTestUrlAnchor[] = "https://google.com/#samepage";
 const char kDefaultTestUrl2[] = "https://whatever.com/";
+const char kFilteredStartUrl[] = "https://whatever.com/ignore-on-start";
 const char kFilteredCommitUrl[] = "https://whatever.com/ignore-on-commit";
 
 // Simple PageLoadMetricsObserver that copies observed PageLoadTimings into the
 // provided std::vector, so they can be analyzed by unit tests.
 class TestPageLoadMetricsObserver : public PageLoadMetricsObserver {
  public:
   TestPageLoadMetricsObserver(std::vector<PageLoadTiming>* updated_timings,
                               std::vector<PageLoadTiming>* complete_timings,
                               std::vector<GURL>* observed_committed_urls)
       : updated_timings_(updated_timings),
         complete_timings_(complete_timings),
         observed_committed_urls_(observed_committed_urls) {}
 
-  void OnStart(content::NavigationHandle* navigation_handle,
+  ObservePolicy OnStart(content::NavigationHandle* navigation_handle,
                const GURL& currently_committed_url,
                bool started_in_foreground) override {
     observed_committed_urls_->push_back(currently_committed_url);
+    return CONTINUE_OBSERVING;
   }
 
   void OnTimingUpdate(const PageLoadTiming& timing,
                       const PageLoadExtraInfo& extra_info) override {
     updated_timings_->push_back(timing);
   }
 
   void OnComplete(const PageLoadTiming& timing,
                   const PageLoadExtraInfo& extra_info) override {
     complete_timings_->push_back(timing);
@@ skipping 12 matching lines @@
 };
 
 // Test PageLoadMetricsObserver that stops observing page loads with certain
 // substrings in the URL.
 class FilteringPageLoadMetricsObserver : public PageLoadMetricsObserver {
  public:
   explicit FilteringPageLoadMetricsObserver(
       std::vector<GURL>* completed_filtered_urls)
       : completed_filtered_urls_(completed_filtered_urls) {}
 
+  ObservePolicy OnStart(content::NavigationHandle* handle,
+                        const GURL& currently_committed_url,
+                        bool started_in_foreground) override {
+    const bool should_ignore =
+        handle->GetURL().spec().find("ignore-on-start") != std::string::npos;
+    return should_ignore ? STOP_OBSERVING : CONTINUE_OBSERVING;
+  }
+
   ObservePolicy OnCommit(content::NavigationHandle* handle) override {
     const bool should_ignore =
         handle->GetURL().spec().find("ignore-on-commit") != std::string::npos;
     return should_ignore ? STOP_OBSERVING : CONTINUE_OBSERVING;
   }
 
   void OnComplete(const PageLoadTiming& timing,
                   const PageLoadExtraInfo& extra_info) override {
     completed_filtered_urls_->push_back(extra_info.committed_url);
   }
@@ skipping 482 matching lines @@
 
   web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl2));
   ASSERT_EQ(std::vector<GURL>({GURL(kDefaultTestUrl)}),
             completed_filtered_urls());
 
   web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl));
   ASSERT_EQ(std::vector<GURL>({GURL(kDefaultTestUrl), GURL(kDefaultTestUrl2)}),
             completed_filtered_urls());
 }
 
+TEST_F(MetricsWebContentsObserverTest, StopObservingOnStart) {
+  content::WebContentsTester* web_contents_tester =
+      content::WebContentsTester::For(web_contents());
+  ASSERT_TRUE(completed_filtered_urls().empty());
+
+  web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl));
+  ASSERT_TRUE(completed_filtered_urls().empty());
+
+  // kFilteredCommitUrl should stop observing in OnStart, and thus should not
+  // reach OnComplete().
+  web_contents_tester->NavigateAndCommit(GURL(kFilteredStartUrl));
+  ASSERT_EQ(std::vector<GURL>({GURL(kDefaultTestUrl)}),
+            completed_filtered_urls());
+
+  web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl2));
+  ASSERT_EQ(std::vector<GURL>({GURL(kDefaultTestUrl)}),
+            completed_filtered_urls());
+
+  web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl));
+  ASSERT_EQ(std::vector<GURL>({GURL(kDefaultTestUrl), GURL(kDefaultTestUrl2)}),
+            completed_filtered_urls());
+}
+
 }  // namespace page_load_metrics