[Merge to M115] Prerender: Record activation defer time per trigger

This CL makes Navigation.Prerender.ActivationCommitDeferTime be recorded per trigger type so that we can analyze if head-start time of prerendering that heavily depends on trigger type is sufficient. Previously this metric was recorded only when PrerenderCommitDeferringCondition defers navigation. After this CL, the metric is recorded even when it doesn't defer as zero delay so that we can see the whole trend of delay due to this condition. (cherry picked from commit 938494a) Bug: 1449242 Change-Id: I494bae2145493f7407c0186c084b2b6725f28265 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4570158 Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org> Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org> Reviewed-by: Lingqi Chi <lingqi@chromium.org> Cr-Original-Commit-Position: refs/heads/main@{#1150378} Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4592531 Cr-Commit-Position: refs/branch-heads/5790@{#395} Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}
chromium · Jun 6, 2023 · c535590 · c535590
1 parent 9e8b218
commit c535590
Show file tree

Hide file tree

Showing 7 changed files with 53 additions and 8 deletions.
diff --git a/content/browser/preloading/prerender/prerender_browsertest.cc b/content/browser/preloading/prerender/prerender_browsertest.cc
@@ -4365,7 +4365,7 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest,
   // "Navigation.Prerender.ActivationCommitDeferTime" histogram should be
   // recorded as PrerenderCommitDeferringCondition defers the navigation.
   histogram_tester().ExpectTotalCount(
-      "Navigation.Prerender.ActivationCommitDeferTime", 1u);
+      "Navigation.Prerender.ActivationCommitDeferTime.SpeculationRule", 1u);
 }
 
 // TODO(https://crbug.com/1182032): Now the File System Access API is not

diff --git a/content/browser/preloading/prerender/prerender_commit_deferring_condition.cc b/content/browser/preloading/prerender/prerender_commit_deferring_condition.cc
@@ -6,6 +6,8 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/task/sequenced_task_runner.h"
+#include "content/browser/preloading/prerender/prerender_host.h"
+#include "content/browser/preloading/prerender/prerender_metrics.h"
 #include "content/browser/renderer_host/frame_tree.h"
 #include "content/browser/renderer_host/frame_tree_node.h"
 #include "content/browser/renderer_host/navigation_request.h"
@@ -68,8 +70,16 @@ PrerenderCommitDeferringCondition::WillCommitNavigation(
 
   // If there is no ongoing main frame navigation in prerender frame tree, the
   // prerender activation is allowed to continue.
-  if (!prerender_frame_tree_node->HasNavigation())
+  if (!prerender_frame_tree_node->HasNavigation()) {
+    // Record the defer waiting time for PrerenderCommitDeferringCondition as no
+    // delay.
+    PrerenderHost& prerender_host =
+        PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
+    RecordPrerenderActivationCommitDeferTime(
+        base::TimeDelta(), prerender_host.trigger_type(),
+        prerender_host.embedder_histogram_suffix());
     return Result::kProceed;
+  }
 
   // Defer the prerender activation until the ongoing prerender main frame
   // navigation commits.
@@ -108,8 +118,11 @@ void PrerenderCommitDeferringCondition::DidFinishNavigation(
 
     // Record the defer waiting time for PrerenderCommitDeferringCondition.
     base::TimeDelta delta = base::TimeTicks::Now() - defer_start_time_;
-    base::UmaHistogramTimes("Navigation.Prerender.ActivationCommitDeferTime",
-                            delta);
+    PrerenderHost& prerender_host =
+        PrerenderHost::GetFromFrameTreeNode(*prerender_frame_tree_node);
+    RecordPrerenderActivationCommitDeferTime(
+        delta, prerender_host.trigger_type(),
+        prerender_host.embedder_histogram_suffix());
   }
 }
 

diff --git a/content/browser/preloading/prerender/prerender_host.cc b/content/browser/preloading/prerender/prerender_host.cc
@@ -120,6 +120,13 @@ PrerenderHost* PrerenderHost::GetPrerenderHostFromFrameTreeNode(
   }
 }
 
+// static
+PrerenderHost& PrerenderHost::GetFromFrameTreeNode(
+    FrameTreeNode& frame_tree_node) {
+  CHECK(frame_tree_node.frame_tree().is_prerendering());
+  return *static_cast<PrerenderHost*>(frame_tree_node.frame_tree().delegate());
+}
+
 PrerenderHost::PrerenderHost(
     const PrerenderAttributes& attributes,
     WebContentsImpl& web_contents,

diff --git a/content/browser/preloading/prerender/prerender_host.h b/content/browser/preloading/prerender/prerender_host.h
@@ -102,6 +102,9 @@ class CONTENT_EXPORT PrerenderHost : public FrameTree::Delegate,
   // frame_tree_node is in a prerendering tree.
   static PrerenderHost* GetPrerenderHostFromFrameTreeNode(
       FrameTreeNode& frame_tree_node);
+  // Similar to GetPrerenderHostFromFrameTreeNode() but `frame_tree_node` must
+  // be in prerendering.
+  static PrerenderHost& GetFromFrameTreeNode(FrameTreeNode& frame_tree_node);
 
   // Checks whether two headers are the same in a case-insensitive and
   // order-insensitive way.

diff --git a/content/browser/preloading/prerender/prerender_metrics.cc b/content/browser/preloading/prerender/prerender_metrics.cc
@@ -441,4 +441,14 @@ void RecordPrerenderBackNavigationEligibility(
   }
 }
 
+void RecordPrerenderActivationCommitDeferTime(
+    base::TimeDelta time_delta,
+    PrerenderTriggerType trigger_type,
+    const std::string& embedder_histogram_suffix) {
+  base::UmaHistogramTimes(
+      GenerateHistogramName("Navigation.Prerender.ActivationCommitDeferTime",
+                            trigger_type, embedder_histogram_suffix),
+      time_delta);
+}
+
 }  // namespace content
diff --git a/content/browser/preloading/prerender/prerender_metrics.h b/content/browser/preloading/prerender/prerender_metrics.h
@@ -196,6 +196,11 @@ void RecordPrerenderBackNavigationEligibility(
     PrerenderBackNavigationEligibility eligibility,
     PreloadingAttempt* preloading_attempt);
 
+void RecordPrerenderActivationCommitDeferTime(
+    base::TimeDelta time_delta,
+    PrerenderTriggerType trigger_type,
+    const std::string& embedder_histogram_suffix);
+
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_METRICS_H_
diff --git a/tools/metrics/histograms/metadata/navigation/histograms.xml b/tools/metrics/histograms/metadata/navigation/histograms.xml
@@ -1237,15 +1237,22 @@ Also used in tools/metrics/histograms/metadata/page/histograms.xml.
   </summary>
 </histogram>
 
-<histogram name="Navigation.Prerender.ActivationCommitDeferTime" units="ms"
-    expires_after="2023-06-04">
-  <owner>sreejakshetty@chromium.org</owner>
-  <owner>altimin@chromium.org</owner>
+<histogram
+    name="Navigation.Prerender.ActivationCommitDeferTime{PrerenderTriggerType}"
+    units="ms" expires_after="2023-11-23">
+  <owner>nhiroki@chromium.org</owner>
+  <owner>chrome-prerendering@chromium.org</owner>
   <summary>
     Measures time a PrerenderCommitDeferringCondition defers activation waiting
     to commit an ongoing mainframe prerender navigation. Logged every time a
     PrerenderCommitDeferringCondition defers navigation.
+
+    After 2023/05, this metric is used with PrerenderTriggerType key and records
+    even when PrerenderCommitDeferringCondition doesn't delay navigation as zero
+    delay. Previously the metric was only used without the key and recorded only
+    when PrerenderCommitDeferringCondition deferred navigation.
   </summary>
+  <token key="PrerenderTriggerType" variants="PrerenderTriggerType"/>
 </histogram>
 
 <histogram name="Navigation.QueueTime.{Method}.{FrameType}" units="ms"