Propogate the tab foreground, background change events to data use

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"
@@ skipping 157 matching lines @@
   DCHECK(!is_initialized_);
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   ascriber_ = ascriber;
   is_initialized_ = true;
 
   for (auto& it : pending_frames_queue_) {
     RenderFrameCreated(it);
   }
   pending_frames_queue_.clear();
+
+  for (const auto& it : pending_visible_main_frames_) {
+    WasShownOrHidden(it, true);

[RyanSturm, 2016/12/13 22:04:19]

Is it possible a frame is created, shown, and deleted before asrciber_ is set?

Maybe move this code into the pending_frames_queue_ loop, something like:

for (auto& it : pending_frames_queue_) {
  RenderFrameCreated(it);
  if (pending_visible_main_frames_.find(it) !=
pending_visible_main_frames_.end()) {
     WasShownOrHidden(it, true);
  }
}
pending_frames_queue_.clear();
pending_visible_main_frames_.clear();

[Raj, 2016/12/14 23:00:50]

Done.

+  }
+  pending_visible_main_frames_.clear();
+}
+
+void ChromeDataUseAscriberService::WasShownOrHidden(
+    content::RenderFrameHost* main_render_frame_host,
+    bool visible) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (!ascriber_) {
+    if (visible)
+      pending_visible_main_frames_.insert(main_render_frame_host);
+    else
+      pending_visible_main_frames_.erase(main_render_frame_host);
+    return;
+  }
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&ChromeDataUseAscriber::WasShownOrHidden,
+                 base::Unretained(ascriber_),
+                 main_render_frame_host->GetProcess()->GetID(),
+                 main_render_frame_host->GetRoutingID(), visible));
+}
+
+void ChromeDataUseAscriberService::RenderFrameHostChanged(
+    content::RenderFrameHost* old_host,
+    content::RenderFrameHost* new_host) {
+  if (!ascriber_)
+    return;
+
+  if (old_host) {
+    content::BrowserThread::PostTask(
+        content::BrowserThread::IO, FROM_HERE,
+        base::Bind(&ChromeDataUseAscriber::RenderFrameHostChanged,
+                   base::Unretained(ascriber_), old_host->GetProcess()->GetID(),
+                   old_host->GetRoutingID(), new_host->GetProcess()->GetID(),
+                   new_host->GetRoutingID()));
+  }
 }
 
 }  // namespace data_use_measurement