Log First User Interaction in Page Load Metrics

components/page_load_metrics/browser/metrics_web_contents_observer.cc

Index: components/page_load_metrics/browser/metrics_web_contents_observer.cc
diff --git a/components/page_load_metrics/browser/metrics_web_contents_observer.cc b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
index 7678a3f4ace6e08330d369f04b13909e94293bf4..7c22cc55971162568caf43576df81b7a5aa7d6a2 100644
--- a/components/page_load_metrics/browser/metrics_web_contents_observer.cc
+++ b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
@@ -20,6 +20,7 @@
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
@@ -30,6 +31,8 @@
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(
     page_load_metrics::MetricsWebContentsObserver);
 
+class RenderViewHost;
+
 namespace page_load_metrics {
 
 namespace internal {
@@ -372,6 +375,12 @@ void PageLoadTracker::Redirect(content::NavigationHandle* navigation_handle) {
   }
 }
 
+void PageLoadTracker::OnInputEvent(const blink::WebInputEvent& event) {
+  for (const auto& observer : observers_) {
+    observer->OnUserInput(event, navigation_start_ - base::TimeTicks::Now());

[Bryan McQuade, 2016/05/27 15:03:31]

I'm inclined to not provide a timestamp in the callback, if it's really just the
current time. Instead, you can compute this in our observer by storing the
current TimeTicks and then taking a delta between that and navigation_start_
time in your observer. If we don't provide the TimeTicks for navigation_start
time to observers currently, I'd be fine with doing so in PageLoadExtraInfo.
Charles, wdyt?

[Bryan McQuade, 2016/05/27 17:31:47]

charles pointed out to me that you can call
navigation_handle->GetNavigationStart() in your OnCommit function to get record
this time. so no change needed to PageLoadExtraInfo.

+  }
+}
+
 bool PageLoadTracker::UpdateTiming(const PageLoadTiming& new_timing,
                                    const PageLoadMetadata& new_metadata) {
   // Throw away IPCs that are not relevant to the current navigation.
@@ -508,7 +517,9 @@ MetricsWebContentsObserver::MetricsWebContentsObserver(
     : content::WebContentsObserver(web_contents),
       in_foreground_(false),
       embedder_interface_(std::move(embedder_interface)),
-      has_navigated_(false) {}
+      has_navigated_(false) {
+  this->RegisterInputEventObserver(web_contents->GetRenderViewHost());

[Bryan McQuade, 2016/05/27 15:03:31]

you can exclude 'this->' when invoking member functions.

+}
 
 MetricsWebContentsObserver* MetricsWebContentsObserver::CreateForWebContents(
     content::WebContents* web_contents,
@@ -521,11 +532,30 @@ MetricsWebContentsObserver* MetricsWebContentsObserver::CreateForWebContents(
                                              std::move(embedder_interface));
     web_contents->SetUserData(UserDataKey(), metrics);
   }
+
   return metrics;
 }
 
 MetricsWebContentsObserver::~MetricsWebContentsObserver() {
   NotifyAbortAllLoads(ABORT_CLOSE);
+  UnregisterInputEventObserver(web_contents()->GetRenderViewHost());
+}
+
+void MetricsWebContentsObserver::RegisterInputEventObserver(
+    content::RenderViewHost* host) {
+  host->GetWidget()->AddInputEventObserver(this);
+}
+
+void MetricsWebContentsObserver::UnregisterInputEventObserver(
+    content::RenderViewHost* host) {
+  host->GetWidget()->RemoveInputEventObserver(this);
+}
+
+void MetricsWebContentsObserver::RenderViewHostChanged(
+    content::RenderViewHost* old_host,
+    content::RenderViewHost* new_host) {
+  UnregisterInputEventObserver(old_host);
+  RegisterInputEventObserver(new_host);
 }
 
 bool MetricsWebContentsObserver::OnMessageReceived(
@@ -663,6 +693,21 @@ void MetricsWebContentsObserver::NavigationStopped() {
   NotifyAbortAllLoads(ABORT_STOP);
 }
 
+bool MetricsWebContentsObserver::OnInputEvent(
+    const blink::WebInputEvent& event) {
+  // Ignore browser navigation or reload which comes with type Undefined.
+  if (event.type == blink::WebInputEvent::Type::Undefined)
+    return false;
+
+  if (!committed_load_) {
+    RecordInternalError(ERR_USER_INPUT_WITH_NO_RELEVANT_LOAD);
+    return false;
+  }
+
+  committed_load_->OnInputEvent(event);
+  return true;
+}
+
 void MetricsWebContentsObserver::DidRedirectNavigation(
     content::NavigationHandle* navigation_handle) {
   if (!navigation_handle->IsInMainFrame())