[Page Load Metrics] PageLoadMetrics Mojofication.

chrome/browser/page_load_metrics/page_load_metrics_mojofication_browsertest.cc

Index: chrome/browser/page_load_metrics/page_load_metrics_mojofication_browsertest.cc
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc b/chrome/browser/page_load_metrics/page_load_metrics_mojofication_browsertest.cc
similarity index 66%
copy from chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
copy to chrome/browser/page_load_metrics/page_load_metrics_mojofication_browsertest.cc
index 8d69c71e8ddf51c0cebb4c566fda09100271e219..aef526fea94b17ac0de2f1ca3cf17c9b6c4a64a6 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_mojofication_browsertest.cc
@@ -5,6 +5,7 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/test/histogram_tester.h"
+#include "base/test/scoped_feature_list.h"
 #include "base/time/time.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.h"
@@ -18,7 +19,7 @@
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_navigator_params.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
-#include "chrome/common/page_load_metrics/page_load_metrics_messages.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/in_process_browser_test.h"
@@ -29,18 +30,34 @@
 #include "content/public/browser/render_view_host.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/download_test_observer.h"
+#include "content/public/test/web_contents_binding_set_test_binder.h"
+#include "mojo/public/cpp/bindings/associated_binding.h"
 #include "net/http/failing_http_transaction_factory.h"
 #include "net/http/http_cache.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "net/test/url_request/url_request_failed_job.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
+#include "testing/gmock/include/gmock/gmock.h"
 
 namespace {
 
-// Waits until a PageLoadMetricsMsg_TimingUpdated message IPC is received
-// matching a PageLoadTiming. See WaitForMatchingIPC for details.
-class TimingUpdatedObserver : public content::BrowserMessageFilter {
+void FailAllNetworkTransactions(net::URLRequestContextGetter* getter) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  net::HttpCache* cache(
+      getter->GetURLRequestContext()->http_transaction_factory()->GetCache());
+  DCHECK(cache);
+  std::unique_ptr<net::FailingHttpTransactionFactory> factory(
+      new net::FailingHttpTransactionFactory(cache->GetSession(),
+                                             net::ERR_FAILED));
+  // Throw away old version; since this is a browser test, there is no
+  // need to restore the old state.
+  cache->SetHttpNetworkTransactionFactoryForTesting(std::move(factory));
+}
+
+// Wait until we dispatch PageLoadTiming through UpdateTiming.
+// matching a PageLoadTiming. See WaitForTimingUpdated for details.
+class PageLoadTimingObserver {
  public:
   // A bitvector to express which timing fields to match on.
   enum ExpectedTimingFields {
@@ -49,20 +66,19 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
     STYLE_UPDATE_BEFORE_FCP = 1 << 2
   };
 
-  explicit TimingUpdatedObserver(content::RenderWidgetHost* render_widget_host)
-      : content::BrowserMessageFilter(PageLoadMetricsMsgStart) {
-    render_widget_host->GetProcess()->AddFilter(this);
-
+  PageLoadTimingObserver() {
     // Roundtrip to the IO thread, to ensure that the filter is properly
     // installed.
     content::BrowserThread::PostTaskAndReply(
-        content::BrowserThread::IO, FROM_HERE, base::BindOnce(&base::DoNothing),
-        base::BindOnce(&TimingUpdatedObserver::Quit, this));
+        content::BrowserThread::IO, FROM_HERE, base::Bind(&base::DoNothing),
+        base::Bind(&PageLoadTimingObserver::Quit, base::Unretained(this)));
     run_loop_.reset(new base::RunLoop());
     run_loop_->Run();
     run_loop_.reset(nullptr);
   }
 
+  ~PageLoadTimingObserver() {}
+
   // Add the given timing fields to the set of fields to match on.
   void AddMatchingFields(ExpectedTimingFields fields) {
     matching_fields_ |= fields;
@@ -74,10 +90,10 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
     match_document_write_block_reload_ = count;
   }
 
+  // Waits for a PageLoadTiming that matches the fields set by
   // Waits for a TimingUpdated IPC that matches the fields set by
-  // |AddMatchingFields|.  All matching fields must be set in a TimingUpdated
-  // IPC for it to end this wait.
-  void WaitForMatchingIPC() {
+  // UpdateTiming to end this wait.
+  void WaitForTimingUpdated() {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
     if (matched_timing_update_)
       return;
@@ -87,19 +103,8 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
     run_loop_.reset(nullptr);
   }
 
- private:
-  bool OnMessageReceived(const IPC::Message& message) override {
-    DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-
-    IPC_BEGIN_MESSAGE_MAP(TimingUpdatedObserver, message)
-      IPC_MESSAGE_HANDLER(PageLoadMetricsMsg_TimingUpdated, OnTimingUpdated)
-    IPC_END_MESSAGE_MAP()
-
-    return false;
-  }
-
-  bool OnTimingUpdated(const page_load_metrics::PageLoadTiming& timing,
-                       const page_load_metrics::PageLoadMetadata& metadata) {
+  void UpdateTiming(const page_load_metrics::PageLoadTiming& timing,
+                    const page_load_metrics::PageLoadMetadata& metadata) {
     if (match_document_write_block_reload_ > 0 &&
         metadata.behavior_flags &
             blink::WebLoadingBehaviorFlag::
@@ -108,7 +113,7 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
     }
 
     if (match_document_write_block_reload_ > 0) {
-      return true;
+      return;
     }
 
     if ((!(matching_fields_ & FIRST_PAINT) ||
@@ -122,17 +127,17 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
       // this waiter unblocks.
       content::BrowserThread::PostTask(
           content::BrowserThread::IO, FROM_HERE,
-          base::BindOnce(&TimingUpdatedObserver::BounceTimingUpdate, this,
-                         timing, metadata));
+          base::Bind(&PageLoadTimingObserver::BounceTimingUpdate,
+                     base::Unretained(this)));
     }
-    return true;
   }
 
-  void BounceTimingUpdate(const page_load_metrics::PageLoadTiming& timing,
-                          const page_load_metrics::PageLoadMetadata& metadata) {
+ private:
+  void BounceTimingUpdate() {
     content::BrowserThread::PostTask(
         content::BrowserThread::UI, FROM_HERE,
-        base::BindOnce(&TimingUpdatedObserver::SetTimingUpdatedAndQuit, this));
+        base::Bind(&PageLoadTimingObserver::SetTimingUpdatedAndQuit,
+                   base::Unretained(this)));
   }
 
   void Quit() {
@@ -147,8 +152,6 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
     Quit();
   }
 
-  ~TimingUpdatedObserver() override {}
-
   std::unique_ptr<base::RunLoop> run_loop_;
   int matching_fields_ = 0;  // A bitvector composed from ExpectedTimingFields.
   bool matched_timing_update_ = false;
@@ -157,10 +160,80 @@ class TimingUpdatedObserver : public content::BrowserMessageFilter {
 
 }  // namespace
 
-class PageLoadMetricsBrowserTest : public InProcessBrowserTest {
+namespace page_load_metrics {
+
+class FakePageLoadMetrics : public mojom::PageLoadMetrics {
+ public:
+  explicit FakePageLoadMetrics(content::RenderFrameHost* render_frame_host) {
+    metrics_observer_ = content::WebContentsUserData<
+        page_load_metrics::MetricsWebContentsObserver>::
+        FromWebContents(
+            content::WebContents::FromRenderFrameHost(render_frame_host));
+    metrics_observer_->page_load_metrics_binding_for_testing()
+        .SetCurrentTargetFrameForTesting(render_frame_host);
+  }
+
+  ~FakePageLoadMetrics() override {}
+
+  void AddObserver(PageLoadTimingObserver* observer) {

[Bryan McQuade, 2017/04/26 16:04:34]

ah, I see now why you have this class and this method. I still worry about
having to stub/wrap so much of the mojo code in a browser test. Ideally we'd be
able to accomplish the goal of waiting for a mojo message to arrive without
having to wrap the mojom::PageLoadMetrics like this.

Ken, the test cases in this file to wait until a message received over the mojo
channel meets a certain constraint before allowing the test to continue. Is
there a canonical/best way for browser tests to do this, without having to wrap
the mojom::PageLoadMetrics object like this?

[Ken Rockot(use gerrit already), 2017/04/26 16:11:41]

The messages are always going to be dispatched to some implementation of
mojom::PageLoadMetrics. You can either do this (dispatch to a test-only impl) or
add testing hooks to the non-test impl. I don't see much room for other options
if a test needs to inspect incoming messages.

[Bryan McQuade, 2017/04/26 20:41:51]

I decided that adding testing hooks to the non-test impl was better overall. It
has no real cost to non-test code, and allows us to avoid having to wrap code in
tests, which I think is desirable.

Peiyong, I put together a change for this here:
https://codereview.chromium.org/2847513002 which I hope eases the rest of your
work to migrate from IPC to mojo. Let me know what you think.

Thanks,
Bryan

[lpy, 2017/04/27 10:58:35]

It looks good.

+    observers_.push_back(base::WrapUnique(observer));
+  }
+
+ private:
+  void UpdateTiming(const PageLoadTiming& timing,
+                    const PageLoadMetadata& metadata) override {
+    metrics_observer_->UpdateTiming(timing, metadata);
+    for (auto& observer : observers_) {
+      observer->UpdateTiming(timing, metadata);
+    }
+  }
+
+  MetricsWebContentsObserver* metrics_observer_;
+  std::vector<std::unique_ptr<PageLoadTimingObserver>> observers_;
+};
+
+}  // namespace page_load_metrics
+
+namespace {
+
+class FakePageLoadMetricsBinder
+    : public content::WebContentsBindingSetTestBinder<
+          page_load_metrics::mojom::PageLoadMetrics> {
+ public:
+  FakePageLoadMetricsBinder(
+      page_load_metrics::mojom::PageLoadMetrics* page_load_metrics)
+      : page_load_metrics_(page_load_metrics) {}
+  ~FakePageLoadMetricsBinder() override {}
+
+  void BindRequest(content::RenderFrameHost* frame_host,
+                   page_load_metrics::mojom::PageLoadMetricsAssociatedRequest
+                       request) override {
+    bindings_.AddBinding(page_load_metrics_, std::move(request), frame_host);
+  }
+
+ private:
+  page_load_metrics::mojom::PageLoadMetrics* page_load_metrics_;
+  mojo::AssociatedBindingSet<page_load_metrics::mojom::PageLoadMetrics,
+                             content::RenderFrameHost*>
+      bindings_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakePageLoadMetricsBinder);
+};
+
+}  // namespace
+
+class PageLoadMetricsMojoficationBrowserTest : public InProcessBrowserTest {
  public:
-  PageLoadMetricsBrowserTest() {}
-  ~PageLoadMetricsBrowserTest() override {}
+  PageLoadMetricsMojoficationBrowserTest() {}
+  ~PageLoadMetricsMojoficationBrowserTest() override {}
+
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    // We need to set the feature state before the render process is created,
+    // in order for it to inherit the feature state from the browser process.
+    // SetUp() runs too early, and SetUpOnMainThread() runs too late.
+    scoped_feature_list_.InitAndEnableFeature(
+        features::kPageLoadMetricsMojofication);
+  }
 
  protected:
   void NavigateToUntrackedUrl() {
@@ -178,39 +251,41 @@ class PageLoadMetricsBrowserTest : public InProcessBrowserTest {
     return total_pageload_histograms - total_internal_histograms == 0;
   }
 
-  scoped_refptr<TimingUpdatedObserver> CreateTimingUpdatedObserver() {
-    content::WebContents* web_contents =
-        browser()->tab_strip_model()->GetActiveWebContents();
-    scoped_refptr<TimingUpdatedObserver> observer(new TimingUpdatedObserver(
-        web_contents->GetRenderViewHost()->GetWidget()));
+  PageLoadTimingObserver* CreatePageLoadTimingObserver() {
+    if (!fake_page_load_metrics_) {
+      content::WebContents* web_contents =
+          browser()->tab_strip_model()->GetActiveWebContents();
+      fake_page_load_metrics_.reset(new page_load_metrics::FakePageLoadMetrics(
+          web_contents->GetMainFrame()));
+      content::WebContentsBindingSet::GetForWebContents<
+          page_load_metrics::mojom::PageLoadMetrics>(web_contents)
+          ->SetBinderForTesting(base::MakeUnique<FakePageLoadMetricsBinder>(
+              fake_page_load_metrics_.get()));
+    }
+    PageLoadTimingObserver* observer = new PageLoadTimingObserver();
+    fake_page_load_metrics_->AddObserver(observer);
     return observer;
   }
 
+  base::test::ScopedFeatureList scoped_feature_list_;
+  std::unique_ptr<page_load_metrics::FakePageLoadMetrics>
+      fake_page_load_metrics_;
   base::HistogramTester histogram_tester_;
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(PageLoadMetricsBrowserTest);
+  DISALLOW_COPY_AND_ASSIGN(PageLoadMetricsMojoficationBrowserTest);
 };
 
-void FailAllNetworkTransactions(net::URLRequestContextGetter* getter) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-  net::HttpCache* cache(
-      getter->GetURLRequestContext()->http_transaction_factory()->GetCache());
-  DCHECK(cache);
-  std::unique_ptr<net::FailingHttpTransactionFactory> factory(
-      new net::FailingHttpTransactionFactory(cache->GetSession(),
-                                             net::ERR_FAILED));
-  // Throw away old version; since this is a browser test, there is no
-  // need to restore the old state.
-  cache->SetHttpNetworkTransactionFactoryForTesting(std::move(factory));
-}
-
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoNavigation) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, NoNavigation) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NewPage) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, NewPage) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -234,7 +309,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NewPage) {
   EXPECT_FALSE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SameDocumentNavigation) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       SameDocumentNavigation) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -248,7 +326,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SameDocumentNavigation) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SameUrlNavigation) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       SameUrlNavigation) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -263,7 +344,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SameUrlNavigation) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 2);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHtmlMainResource) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       NonHtmlMainResource) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -272,7 +356,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHtmlMainResource) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHttpOrHttpsUrl) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       NonHttpOrHttpsUrl) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIVersionURL));
@@ -280,7 +367,9 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHttpOrHttpsUrl) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, HttpErrorPage) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, HttpErrorPage) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
@@ -289,7 +378,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, HttpErrorPage) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, ChromeErrorPage) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       ChromeErrorPage) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   // Configure the network stack to fail all attempted loads with a network
@@ -298,8 +390,8 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, ChromeErrorPage) {
       browser()->profile()->GetRequestContext();
   content::BrowserThread::PostTask(
       content::BrowserThread::IO, FROM_HERE,
-      base::BindOnce(&FailAllNetworkTransactions,
-                     base::RetainedRef(url_request_context_getter)));
+      base::Bind(&FailAllNetworkTransactions,
+                 base::RetainedRef(url_request_context_getter)));
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
@@ -307,7 +399,9 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, ChromeErrorPage) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, Ignore204Pages) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, Ignore204Pages) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -316,7 +410,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, Ignore204Pages) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, IgnoreDownloads) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       IgnoreDownloads) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   base::ScopedTempDir downloads_directory;
@@ -336,24 +433,29 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, IgnoreDownloads) {
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, PreloadDocumentWrite) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       PreloadDocumentWrite) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_external_script.html"));
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteParseStartToFirstContentfulPaint, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoPreloadDocumentWrite) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       NoPreloadDocumentWrite) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
@@ -365,17 +467,19 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoPreloadDocumentWrite) {
       internal::kHistogramDocWriteParseStartToFirstContentfulPaint, 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoDocumentWrite) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       NoDocumentWrite) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteParseStartToFirstContentfulPaint, 0);
@@ -384,33 +488,36 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoDocumentWrite) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteBlock) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       DocumentWriteBlock) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_script_block.html"));
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteReload) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       DocumentWriteReload) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
-  scoped_refptr<TimingUpdatedObserver> reload_observer =
-      CreateTimingUpdatedObserver();
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
+  PageLoadTimingObserver* reload_observer = CreatePageLoadTimingObserver();
   reload_observer->MatchDocumentWriteBlockReload(2);
 
   ui_test_utils::NavigateToURL(
@@ -429,8 +536,8 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteReload) {
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
 
-  fcp_observer->WaitForMatchingIPC();
-  reload_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
+  reload_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
@@ -440,7 +547,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteReload) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteAsync) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       DocumentWriteAsync) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
@@ -453,7 +563,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteAsync) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteSameDomain) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       DocumentWriteSameDomain) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
@@ -466,7 +579,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteSameDomain) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoDocumentWriteScript) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       NoDocumentWriteScript) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
@@ -479,18 +595,13 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoDocumentWriteScript) {
   histogram_tester_.ExpectTotalCount(internal::kHistogramDocWriteBlockCount, 0);
 }
 
-// TODO(crbug.com/712935): Flaky on Linux dbg.
-#if defined(OS_LINUX) && !defined(NDEBUG)
-#define MAYBE_BadXhtml DISABLED_BadXhtml
-#else
-#define MAYBE_BadXhtml BadXhtml
-#endif
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, MAYBE_BadXhtml) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, BadXhtml) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> timing_observer =
-      CreateTimingUpdatedObserver();
-  timing_observer->AddMatchingFields(TimingUpdatedObserver::FIRST_PAINT);
+  PageLoadTimingObserver* timing_observer = CreatePageLoadTimingObserver();
+  timing_observer->AddMatchingFields(PageLoadTimingObserver::FIRST_PAINT);
 
   // When an XHTML page contains invalid XML, it causes a paint of the error
   // message without a layout. Page load metrics currently treats this as an
@@ -501,7 +612,7 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, MAYBE_BadXhtml) {
       browser(),
       embedded_test_server()->GetURL("/page_load_metrics/badxml.xhtml"));
 
-  timing_observer->WaitForMatchingIPC();
+  timing_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 0);
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstPaint, 0);
@@ -521,7 +632,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, MAYBE_BadXhtml) {
 // Test code that aborts provisional navigations.
 // TODO(csharrison): Move these to unit tests once the navigation API in content
 // properly calls NavigationHandle/NavigationThrottle methods.
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortNewNavigation) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       AbortNewNavigation) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
@@ -544,7 +658,9 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortNewNavigation) {
       internal::kHistogramAbortNewNavigationBeforeCommit, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortReload) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, AbortReload) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
@@ -571,7 +687,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortReload) {
 #else
 #define MAYBE_AbortClose AbortClose
 #endif
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, MAYBE_AbortClose) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
+                       MAYBE_AbortClose) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
@@ -590,7 +709,9 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, MAYBE_AbortClose) {
                                      1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortMultiple) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, AbortMultiple) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
@@ -625,8 +746,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortMultiple) {
       internal::kHistogramAbortNewNavigationBeforeCommit, 2);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
                        NoAbortMetricsOnClientRedirect) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL first_url(embedded_test_server()->GetURL("/title1.html"));
@@ -655,8 +778,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
                   .empty());
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
                        FirstMeaningfulPaintRecorded) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
@@ -670,33 +795,34 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
       kNetworkIdleTime + kMargin);
   bool result;
   EXPECT_TRUE(content::ExecuteScriptAndExtractBool(
-      browser()->tab_strip_model()->GetActiveWebContents(),
-      javascript, &result));
+      browser()->tab_strip_model()->GetActiveWebContents(), javascript,
+      &result));
   EXPECT_TRUE(result);
 
   NavigateToUntrackedUrl();
   histogram_tester_.ExpectUniqueSample(
       internal::kHistogramFirstMeaningfulPaintStatus,
       internal::FIRST_MEANINGFUL_PAINT_RECORDED, 1);
-  histogram_tester_.ExpectTotalCount(
-      internal::kHistogramFirstMeaningfulPaint, 1);
+  histogram_tester_.ExpectTotalCount(internal::kHistogramFirstMeaningfulPaint,
+                                     1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseStartToFirstMeaningfulPaint, 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
                        FirstMeaningfulPaintNotRecorded) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/page_with_active_connections.html"));
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   // Navigate away before a FMP is reported.
   NavigateToUntrackedUrl();
@@ -704,25 +830,26 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
   histogram_tester_.ExpectUniqueSample(
       internal::kHistogramFirstMeaningfulPaintStatus,
       internal::FIRST_MEANINGFUL_PAINT_DID_NOT_REACH_NETWORK_STABLE, 1);
-  histogram_tester_.ExpectTotalCount(
-      internal::kHistogramFirstMeaningfulPaint, 0);
+  histogram_tester_.ExpectTotalCount(internal::kHistogramFirstMeaningfulPaint,
+                                     0);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseStartToFirstMeaningfulPaint, 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
                        NoStatePrefetchObserverCacheable) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
 
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       "Prerender.none_PrefetchTTFCP.Reference.NoStore.Visible", 0);
@@ -730,19 +857,20 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
       "Prerender.none_PrefetchTTFCP.Reference.Cacheable.Visible", 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest,
                        NoStatePrefetchObserverNoStore) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::FIRST_CONTENTFUL_PAINT);
+      PageLoadTimingObserver::FIRST_CONTENTFUL_PAINT);
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/nostore.html"));
 
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(
       "Prerender.none_PrefetchTTFCP.Reference.NoStore.Visible", 1);
@@ -750,13 +878,14 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
       "Prerender.none_PrefetchTTFCP.Reference.Cacheable.Visible", 0);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, CSSTiming) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, CSSTiming) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
-  scoped_refptr<TimingUpdatedObserver> fcp_observer =
-      CreateTimingUpdatedObserver();
+  PageLoadTimingObserver* fcp_observer = CreatePageLoadTimingObserver();
   fcp_observer->AddMatchingFields(
-      TimingUpdatedObserver::STYLE_UPDATE_BEFORE_FCP);
+      PageLoadTimingObserver::STYLE_UPDATE_BEFORE_FCP);
 
   // Careful: Blink code clamps timestamps to 5us, so any CSS parsing we do here
   // must take >> 5us, otherwise we'll log 0 for the value and it will remain
@@ -765,7 +894,7 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, CSSTiming) {
       browser(),
       embedded_test_server()->GetURL("/page_load_metrics/page_with_css.html"));
   NavigateToUntrackedUrl();
-  fcp_observer->WaitForMatchingIPC();
+  fcp_observer->WaitForTimingUpdated();
 
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstContentfulPaint,
                                      1);
@@ -777,7 +906,9 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, CSSTiming) {
       "PageLoad.CSSTiming.ParseAndUpdate.BeforeFirstContentfulPaint", 1);
 }
 
-IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, PayloadSize) {
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsMojoficationBrowserTest, PayloadSize) {
+  ASSERT_TRUE(
+      base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication));
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(), embedded_test_server()->GetURL(