Framework to ascribe all network data use to a source.

chrome/browser/data_use_measurement/chrome_data_use_ascriber_service.cc

+// Copyright 2016 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/browser/data_use_measurement/chrome_data_use_ascriber_service.h"
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/data_use_measurement/chrome_data_use_ascriber.h"
+#include "chrome/browser/io_thread.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+
+namespace data_use_measurement {
+
+ChromeDataUseAscriberService::ChromeDataUseAscriberService()
+    : ascriber_(nullptr) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  // Skip IO thread initialization if there is no IO thread. This check is
+  // required because unit tests that do no set up an IO thread cause this
+  // code to execute.
+  if (!g_browser_process->io_thread())
+    return;
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&ChromeDataUseAscriberService::InitOnIOThread,
+                 base::Unretained(this), g_browser_process->io_thread()));
+}
+
+ChromeDataUseAscriberService::~ChromeDataUseAscriberService() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+}
+
+void ChromeDataUseAscriberService::RenderFrameCreated(

[bengr, 2016/09/01 00:16:55]

So rather than posting data use from every request to the UI thread, you post
render frame events to the IO thread. Have you thought about plumbing data use
info through Blink instead, on existing IPC?

[Not at Google. Contact bengr, 2016/09/07 23:38:37]

Yes, the design doc talk about these possibilities and why they were ruled out.
We should send it out to a wider audience in case I am missing something.

+    content::RenderFrameHost* render_frame_host) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_)

[bengr, 2016/09/01 00:16:55]

Why wouldn't the service have an ascriber?

[Not at Google. Contact bengr, 2016/09/07 23:38:37]

During startup, frame events might be called on the UI thread before ascriber_
is set on the IO thread.

+    return;
+
+  int parent_render_process_id = -1;
+  int parent_render_frame_id = -1;
+  if (render_frame_host->GetParent()) {
+    parent_render_process_id =
+        render_frame_host->GetParent()->GetProcess()->GetID();
+    parent_render_frame_id = render_frame_host->GetParent()->GetRoutingID();
+  }
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&ChromeDataUseAscriber::RenderFrameCreated,
+                 base::Unretained(ascriber_),
+                 render_frame_host->GetProcess()->GetID(),
+                 render_frame_host->GetRoutingID(), parent_render_process_id,
+                 parent_render_frame_id));
+}
+
+void ChromeDataUseAscriberService::RenderFrameDeleted(
+    content::RenderFrameHost* render_frame_host) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_)
+    return;
+
+  int parent_render_process_id, parent_render_frame_id = -1;
+
+  if (render_frame_host->GetParent()) {
+    parent_render_process_id =
+        render_frame_host->GetParent()->GetProcess()->GetID();
+    parent_render_frame_id = render_frame_host->GetParent()->GetRoutingID();
+  }
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&ChromeDataUseAscriber::RenderFrameDeleted,
+                 base::Unretained(ascriber_),
+                 render_frame_host->GetProcess()->GetID(),
+                 render_frame_host->GetRoutingID(), parent_render_process_id,
+                 parent_render_frame_id));
+}
+
+void ChromeDataUseAscriberService::DidStartNavigation(
+    content::NavigationHandle* navigation_handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_)
+    return;
+
+  if (navigation_handle->IsInMainFrame()) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(
+            &ChromeDataUseAscriber::DidStartMainFrameNavigation,
+            base::Unretained(ascriber_), navigation_handle->GetURL(),
+            navigation_handle->GetWebContents()
+                ->GetRenderProcessHost()
+                ->GetID(),
+            navigation_handle->GetWebContents()->GetMainFrame()->GetRoutingID(),
+            navigation_handle));
+  }
+}
+
+void ChromeDataUseAscriberService::DidFinishNavigation(
+    content::NavigationHandle* navigation_handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_)
+    return;
+
+  if (navigation_handle->IsInMainFrame()) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(
+            &ChromeDataUseAscriber::DidFinishMainFrameNavigation,
+            base::Unretained(ascriber_), navigation_handle->GetURL(),
+            navigation_handle->GetWebContents()
+                ->GetRenderProcessHost()
+                ->GetID(),
+            navigation_handle->GetWebContents()->GetMainFrame()->GetRoutingID(),
+            !navigation_handle->HasCommitted() ||
+                navigation_handle->IsSamePage(),
+            navigation_handle));
+  }
+}
+
+void ChromeDataUseAscriberService::DidRedirectNavigation(
+    content::NavigationHandle* navigation_handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_)
+    return;
+
+  if (navigation_handle->IsInMainFrame()) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(
+            &ChromeDataUseAscriber::DidRedirectMainFrameNavigation,
+            base::Unretained(ascriber_), navigation_handle->GetURL(),
+            navigation_handle->GetWebContents()
+                ->GetRenderProcessHost()
+                ->GetID(),
+            navigation_handle->GetWebContents()->GetMainFrame()->GetRoutingID(),
+            navigation_handle));
+  }
+}
+
+void ChromeDataUseAscriberService::InitOnIOThread(IOThread* io_thread) {

[bengr, 2016/09/01 00:16:55]

Obviously, you need tests for all of this.

[Not at Google. Contact bengr, 2016/09/07 23:38:37]

Done.

+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(&ChromeDataUseAscriberService::SetDataUseAscriber,
+                 base::Unretained(this),
+                 io_thread->globals()->data_use_ascriber.get()));
+}
+
+void ChromeDataUseAscriberService::SetDataUseAscriber(
+    ChromeDataUseAscriber* ascriber) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  ascriber_ = ascriber;
+}
+
+}  // namespace data_use_measurement