PageLoadMetrics renderer and browser implementation.

components/page_load_metrics/renderer/page_load_metrics_render_frame_observer.cc

+// Copyright 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 "base/time/time.h"
+#include "base/timer/timer.h"
+#include "components/page_load_metrics/renderer/page_load_metrics_render_frame_observer.h"
+#include "components/page_load_metrics/renderer/page_timing_metrics_sender.h"
+#include "content/public/renderer/render_frame.h"
+#include "third_party/WebKit/public/platform/WebURLResponse.h"
+#include "third_party/WebKit/public/web/WebDataSource.h"
+#include "third_party/WebKit/public/web/WebDocument.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebPerformance.h"
+#include "url/gurl.h"
+
+namespace page_load_metrics {
+
+MainRenderFrameObserver::MainRenderFrameObserver(
+    content::RenderFrame* render_frame)
+    : content::RenderFrameObserver(render_frame) {}
+
+MainRenderFrameObserver::~MainRenderFrameObserver() {}
+
+void MainRenderFrameObserver::OnStop() {
+  SendMetrics();
+}
+
+// TODO(bmcquade): use DidChangePerformanceTiming instead, once available.
+// CL 1289053003
+void MainRenderFrameObserver::DidFinishDocumentLoad() {
+  SendMetrics();
+}
+
+// TODO(bmcquade): use DidChangePerformanceTiming instead, once available.
+// CL 1289053003
+void MainRenderFrameObserver::DidFinishLoad() {
+  SendMetrics();
+}
+
+void MainRenderFrameObserver::DidFailProvisionalLoad(
+    const blink::WebURLError& e) {
+  SendMetrics();
+}
+
+void MainRenderFrameObserver::DidCommitProvisionalLoad(
+    bool is_new_navigation,
+    bool is_same_page_navigation) {
+  // Same-page navigations (e.g. an in-document navigation from a fragment
+  // link) aren't full page loads, since they don't go to network to load the
+  // main HTML resource. DidStartProvisionalLoad doesn't get invoked for same
+  // page navigations, so we may still have an active
+  // page_timing_metrics_sender_ at this point.
+  if (is_same_page_navigation)
+    return;
+
+  // We only create a PageTimingMetricsSender if the page meets the criteria for
+  // sending and recording metrics. Once page_timing_metrics_sender_ is
+  // non-null, we will send metrics for the current page at some later time, as
+  // those metrics become available.
+  if (ShouldSendMetrics()) {

[Bryan McQuade, 2015/09/04 20:53:18]

can get rid of the braces here

[Charlie Harrison, 2015/09/08 23:05:15]

Is this in the style guide? I think braces are good because we have a 2 line
block.

[Bryan McQuade, 2015/09/09 16:26:25]

Ah, you're right - I had assumed any single-statement if block could omit, but
it sounds like style guide allows omitting when the statements are short. So
let's keep it as you have it. Style guide for this is here:
https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Conditionals

+    page_timing_metrics_sender_.reset(
+        new PageTimingMetricsSender(this, routing_id(), CreateTimer()));
+  }
+}
+
+void MainRenderFrameObserver::SendMetrics() {
+  if (!page_timing_metrics_sender_)
+    return;
+
+  PageLoadTiming timing(GetTiming());
+  page_timing_metrics_sender_->Send(timing);
+}
+
+bool MainRenderFrameObserver::ShouldSendMetrics() const {
+  const blink::WebLocalFrame& frame = *render_frame()->GetWebFrame();
+  // We only generate historgrams for main frames.
+  if (frame.parent())
+    return false;
+
+  const blink::WebDocument& document = frame.document();
+  // Ignore non-HTTP schemes (e.g. chrome://).
+  const GURL& url = document.url();
+  if (!url.SchemeIsHTTPOrHTTPS())
+    return false;
+
+  const blink::WebURLResponse& url_response = frame.dataSource()->response();
+  // Ignore multipart responses (e.g. MHTML).
+  if (url_response.isMultipartPayload())
+    return false;
+
+  // Ignore non-HTML documents (e.g. SVG). Note that images are treated by
+  // Blink as HTML documents, so to exclude images, we must perform
+  // additional mime type checking below.
+  if (!document.isHTMLDocument() && !document.isXHTMLDocument())
+    return false;
+
+  // Ignore non-HTML mime types (e.g. images).
+  std::string mime_type = url_response.mimeType().utf8();
+  if (mime_type != "text/html" && mime_type != "application/xhtml+xml")
+    return false;
+
+  return true;
+}
+
+PageLoadTiming MainRenderFrameObserver::GetTiming() const {
+  blink::WebLocalFrame* frame = render_frame()->GetWebFrame();
+  if (frame) {

[Bryan McQuade, 2015/09/04 20:53:18]

once you fold the line below, can get rid of braces

[Charlie Harrison, 2015/09/08 23:05:15]

Done.

+    blink::WebPerformance performance = frame->performance();

[Bryan McQuade, 2015/09/04 20:53:18]

can get rid of this line and just fold it into the next line

[Charlie Harrison, 2015/09/08 23:05:15]

Done.

+    return PageLoadTiming(performance);
+  }
+  return PageLoadTiming();
+}
+
+scoped_ptr<base::Timer> MainRenderFrameObserver::CreateTimer() const {
+  return scoped_ptr<base::Timer>(
+      new base::OneShotTimer<PageTimingMetricsSender>());

[Bryan McQuade, 2015/09/04 20:53:18]

I never fully understood how the template parameter is used here, and whether
PageTimingMetricsSender is the right choice. can you look over the timer code
and see what the template param is used for, and whether PageTimingMetricsSender
is the right thing for us to use?

[Charlie Harrison, 2015/09/08 23:05:15]

This is the right way to do it, we need the class to properly call the method
Send() on the object. It's just an implementation detail.

+}
+
+}  // namespace page_load_metrics