[Page Load Metrics] PageLoadMetrics Mojofication.

chrome/renderer/page_load_metrics/page_timing_sender.cc

+// Copyright 2017 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 "chrome/renderer/page_load_metrics/page_timing_sender.h"
+
+#include "base/feature_list.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/common/chrome_features.h"
+#include "chrome/common/page_load_metrics/page_load_metrics.mojom.h"
+#include "chrome/common/page_load_metrics/page_load_metrics_messages.h"
+#include "content/public/common/associated_interface_provider.h"
+#include "content/public/renderer/render_frame.h"
+#include "ipc/ipc_sender.h"
+
+namespace page_load_metrics {
+
+class LegacyIPCPageTimingSender : public IPC::Sender, public PageTimingSender {

[Bryan McQuade, 2017/05/19 14:06:18]

does this need to implement IPC::Sender anymore? seems like the Send() method
can just be inlined into SendTiming now

[lpy, 2017/05/19 23:52:38]

Done.

+ public:
+  LegacyIPCPageTimingSender(content::RenderFrame* render_frame,
+                            const int routing_id)
+      : render_frame_(render_frame), routing_id_(routing_id) {}

[Bryan McQuade, 2017/05/19 14:06:18]

can the render frame ever be null? iirc we had some checks for this when we used
the concrete sender class in unit tests, but with your refactor, maybe we can be
certain that we never receive a null renderframe here? you do dcheck this
condition in the mojo sender so it seems like it's probably a valid assumption
for this class as well.

[lpy, 2017/05/19 23:52:38]

Done.

+  ~LegacyIPCPageTimingSender() override {}
+
+  void SendTiming(const mojom::PageLoadTimingPtr& timing,
+                  const mojom::PageLoadMetadataPtr& metadata) override {
+    Send(new PageLoadMetricsMsg_TimingUpdated(routing_id_, *timing, *metadata));
+  }
+
+ private:
+  // IPC::Sender implementation.
+  bool Send(IPC::Message* message) override {

[Bryan McQuade, 2017/05/19 14:06:18]

let's inline this up into SendTiming() above

[lpy, 2017/05/19 23:52:38]

Done.

+    if (render_frame_)
+      return render_frame_->Send(message);
+    delete message;

[Bryan McQuade, 2017/05/19 14:06:19]

do we want to delete here? I was under the impression that the RenderFrame takes
ownership and manages the object lifetime

[lpy, 2017/05/19 23:52:38]

https://cs.chromium.org/chromium/src/content/public/renderer/render_frame_obs...

+    return false;
+  }
+
+  content::RenderFrame* render_frame_ = nullptr;
+  const int routing_id_;
+};
+
+class MojoIPCPageTimingSender : public PageTimingSender {
+ public:
+  explicit MojoIPCPageTimingSender(content::RenderFrame* render_frame)
+      : render_frame_(render_frame) {}
+  ~MojoIPCPageTimingSender() override {}
+  void SendTiming(const mojom::PageLoadTimingPtr& timing,
+                  const mojom::PageLoadMetadataPtr& metadata) override {
+    DCHECK(render_frame_ && render_frame_->GetWebFrame());
+    if (!page_load_metrics_) {

[Bryan McQuade, 2017/05/19 14:06:18]

I'd rather initialize this in the constructor (instead of lazily in the send
method). That also allow us to avoid keeping render_frame_ as a member.

[lpy, 2017/05/19 23:52:38]

Done.

+      render_frame_->GetRemoteAssociatedInterfaces()->GetInterface(
+          &page_load_metrics_);
+    }
+    page_load_metrics_->UpdateTiming(timing->Clone(), metadata->Clone());
+  }
+
+ private:
+  content::RenderFrame* const render_frame_;
+  // Use associated interface to make sure mojo messages are ordered with regard
+  // to legacy IPC messages.
+  mojom::PageLoadMetricsAssociatedPtr page_load_metrics_;
+};
+
+// static
+std::unique_ptr<PageTimingSender> PageTimingSender::CreatePageTimingSender(
+    content::RenderFrame* render_frame,
+    const int routing_id) {
+  if (base::FeatureList::IsEnabled(features::kPageLoadMetricsMojofication)) {
+    return base::WrapUnique<PageTimingSender>(
+        new MojoIPCPageTimingSender(render_frame));
+  }
+  return base::WrapUnique<PageTimingSender>(
+      new LegacyIPCPageTimingSender(render_frame, routing_id));
+}
+
+}  // namespace page_load_metrics