Decouple prerender from page_load_metrics impl

Added IsPrerender() in PageLoadMetricsEmbedderInterface, so we can
decouple prerender from page_load_metrics implementation.

Bug: 995880
Change-Id: I5088afc7a80f3a050e09f1a827a1d80767a41f1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1796314Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Commit-Queue: Tao Bai <michaelbai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695414}

chrome/browser/page_load_metrics/metrics_web_contents_observer.cc

@@ -16,7 +16,6 @@
 #include "chrome/browser/page_load_metrics/page_load_metrics_update_dispatcher.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
-#include "chrome/browser/prerender/prerender_contents.h"
 #include "components/page_load_metrics/common/page_load_timing.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/global_request_id.h"
@@ -95,9 +94,7 @@ MetricsWebContentsObserver::MetricsWebContentsObserver(
       page_load_metrics_binding_(web_contents, this) {
   // Prerenders erroneously report that they are initially visible, so we
   // manually override visibility state for prerender.
-  const bool is_prerender =
-      prerender::PrerenderContents::FromWebContents(web_contents) != nullptr;
-  if (is_prerender)
+  if (embedder_interface_->IsPrerender(web_contents))
     in_foreground_ = false;
 
   RegisterInputEventObserver(web_contents->GetRenderViewHost());

chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc

@@ -17,6 +17,7 @@
 #include "chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
+#include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "components/page_load_metrics/common/test/weak_mock_timer.h"
@@ -184,6 +185,9 @@ class TestPageLoadMetricsEmbedderInterface
     SetMockTimer(timer->AsWeakPtr());
     return std::move(timer);
   }
+  bool IsPrerender(content::WebContents* web_contents) override {
+    return prerender::PrerenderContents::FromWebContents(web_contents);
+  }
   const std::vector<mojom::PageLoadTimingPtr>& updated_timings() const {
     return updated_timings_;
   }

chrome/browser/page_load_metrics/observers/page_load_metrics_observer_tester.cc

@@ -12,6 +12,7 @@
 #include "base/timer/timer.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h"
+#include "chrome/browser/prerender/prerender_contents.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_data.h"
 #include "content/public/browser/media_player_id.h"
 #include "content/public/browser/render_frame_host.h"
@@ -49,6 +50,10 @@ class TestPageLoadMetricsEmbedderInterface
     return std::move(timer);
   }
 
+  bool IsPrerender(content::WebContents* web_contents) override {
+    return prerender::PrerenderContents::FromWebContents(web_contents);
+  }
+
  private:
   PageLoadMetricsObserverTester* test_;
 

chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h

@@ -13,6 +13,10 @@ namespace base {
 class OneShotTimer;
 }  // namespace base
 
+namespace content {
+class WebContents;
+}  // namespace content
+
 namespace page_load_metrics {
 
 class PageLoadTracker;
@@ -25,6 +29,7 @@ class PageLoadMetricsEmbedderInterface {
   virtual bool IsNewTabPageUrl(const GURL& url) = 0;
   virtual void RegisterObservers(PageLoadTracker* metrics) = 0;
   virtual std::unique_ptr<base::OneShotTimer> CreateTimer() = 0;
+  virtual bool IsPrerender(content::WebContents* web_contents) = 0;
 };
 
 }  // namespace page_load_metrics

chrome/browser/page_load_metrics/page_load_metrics_initialize.cc

@@ -72,6 +72,7 @@ class PageLoadMetricsEmbedder
   bool IsNewTabPageUrl(const GURL& url) override;
   void RegisterObservers(page_load_metrics::PageLoadTracker* tracker) override;
   std::unique_ptr<base::OneShotTimer> CreateTimer() override;
+  bool IsPrerender(content::WebContents* web_contents) override;
 
  private:
   bool IsPrerendering() const;
@@ -186,6 +187,10 @@ bool PageLoadMetricsEmbedder::IsNewTabPageUrl(const GURL& url) {
   return search::IsInstantNTPURL(url, profile);
 }
 
+bool PageLoadMetricsEmbedder::IsPrerender(content::WebContents* web_contents) {
+  return prerender::PrerenderContents::FromWebContents(web_contents);
+}
+
 }  // namespace
 
 void InitializePageLoadMetricsForWebContents(

chrome/browser/page_load_metrics/page_load_tracker.cc

@@ -13,10 +13,8 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/time/default_tick_clock.h"
 #include "base/trace_event/trace_event.h"
-#include "chrome/browser/browser_process.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
-#include "chrome/browser/prerender/prerender_contents.h"
 #include "components/page_load_metrics/common/page_load_timing.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_handle.h"
@@ -199,11 +197,8 @@ PageLoadTracker::PageLoadTracker(
 
   UMA_HISTOGRAM_BOOLEAN(internal::kPageLoadStartedInForeground,
                         started_in_foreground_);
-  const bool is_prerender = prerender::PrerenderContents::FromWebContents(
-                                navigation_handle->GetWebContents()) != nullptr;
-  if (is_prerender) {
+  if (embedder_interface_->IsPrerender(navigation_handle->GetWebContents()))
     UMA_HISTOGRAM_BOOLEAN(internal::kPageLoadPrerender, true);
-  }
 }
 
 PageLoadTracker::~PageLoadTracker() {