ResourceScheduler get visual signal from RenderViewHostImpl

content/browser/loader/resource_scheduler.cc

Index: content/browser/loader/resource_scheduler.cc
diff --git a/content/browser/loader/resource_scheduler.cc b/content/browser/loader/resource_scheduler.cc
index 85adbdb30e275631b53af88286e75b658e73a16c..7207907fff9cf9bfd7c40eab97a7cbf3aae5eb93 100644
--- a/content/browser/loader/resource_scheduler.cc
+++ b/content/browser/loader/resource_scheduler.cc
@@ -12,6 +12,7 @@
 #include "content/public/browser/resource_controller.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/resource_throttle.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "ipc/ipc_message_macros.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_flags.h"
@@ -228,10 +229,15 @@ void ResourceScheduler::RequestQueue::Insert(
 }
 
 // Each client represents a tab.
-class ResourceScheduler::Client {
+class ResourceScheduler::Client : public content::WebContentsObserver {
  public:
-  explicit Client(ResourceScheduler* scheduler)
-      : is_audible_(false),
+  explicit Client(ResourceScheduler* scheduler,
+                  int child_id,
+                  int route_id,
+                  WebContents* web_contents)
+      : child_id_(child_id),
+        route_id_(route_id),
+        is_audible_(false),
         is_visible_(false),
         is_loaded_(false),
         is_paused_(false),
@@ -240,9 +246,10 @@ class ResourceScheduler::Client {
         total_delayable_count_(0),
         throttle_state_(ResourceScheduler::THROTTLED) {
     scheduler_ = scheduler;
+    Observe(web_contents);

[aiolos (Not reviewing), 2014/08/13 21:40:33]

Do you need to set the initial visibility on Client creation, or will WasShown
always be called after Client creation? I thought it was the former, but it's
been a while since I looked. Have you tested the case of the initial foreground
tab to make sure it's marked as visible?

[Zhen Wang, 2014/08/14 22:19:52]

I set the visibility here now. Test added.

On 2014/08/13 21:40:33, aiolos wrote:

   }
 
-  ~Client() {
+  virtual ~Client() {
     // Update to default state and pause to ensure the scheduler has a
     // correct count of relevant types of clients.
     is_visible_ = false;
@@ -251,6 +258,16 @@ class ResourceScheduler::Client {
     UpdateThrottleState();
   }
 
+  // WebContentsObserver implementation.
+  virtual void WasShown() OVERRIDE {
+    scheduler_->OnVisibilityChanged(child_id_, route_id_, true);

[aiolos (Not reviewing), 2014/08/13 21:40:33]

This makes a longer loop than needed to set the information. Ie Client ->
ResourceScheduler -> Client. Just call the Client::OnVisibilityChanged directly
from here.

You can just remove ResourceScheduler::OnVisibilityChanged.

[Zhen Wang, 2014/08/14 22:19:52]

Done.

+  }
+
+  // WebContentsObserver implementation.
+  virtual void WasHidden() OVERRIDE {
+    scheduler_->OnVisibilityChanged(child_id_, route_id_, false);

[aiolos (Not reviewing), 2014/08/13 21:40:33]

Same as above.

[Zhen Wang, 2014/08/14 22:19:52]

Done.

+  }
+
   void ScheduleRequest(
       net::URLRequest* url_request,
       ScheduledResourceRequest* request) {
@@ -288,6 +305,8 @@ class ResourceScheduler::Client {
 
   bool is_loaded() const { return is_loaded_; }
 
+  bool IsVisible() const { return is_visible_; }
+
   void OnAudibilityChanged(bool is_audible) {
     if (is_audible == is_audible_) {
       return;
@@ -647,6 +666,8 @@ class ResourceScheduler::Client {
     }
   }
 
+  const int child_id_;
+  const int route_id_;
   bool is_audible_;
   bool is_visible_;
   bool is_loaded_;
@@ -731,12 +752,14 @@ void ResourceScheduler::RemoveRequest(ScheduledResourceRequest* request) {
   client->RemoveRequest(request);
 }
 
-void ResourceScheduler::OnClientCreated(int child_id, int route_id) {
+void ResourceScheduler::OnClientCreated(int child_id,
+                                        int route_id,
+                                        WebContents* web_contents) {
   DCHECK(CalledOnValidThread());
   ClientId client_id = MakeClientId(child_id, route_id);
   DCHECK(!ContainsKey(client_map_, client_id));
 
-  Client* client = new Client(this);
+  Client* client = new Client(this, child_id, route_id, web_contents);
   client_map_[client_id] = client;
 
   // TODO(aiolos): set Client visibility/audibility when signals are added
@@ -833,6 +856,12 @@ void ResourceScheduler::OnLoadingStateChanged(int child_id,
   client->OnLoadingStateChanged(is_loaded);
 }
 
+bool ResourceScheduler::ClientIsVisible(int child_id, int route_id) {

[aiolos (Not reviewing), 2014/08/13 21:40:33]

nit: IsClientVisible instead.

[Zhen Wang, 2014/08/14 22:19:52]

Done.

+  Client* client = GetClient(child_id, route_id);
+  DCHECK(client);
+  return client->IsVisible();
+}
+
 ResourceScheduler::Client* ResourceScheduler::GetClient(int child_id,
                                                         int route_id) {
   ClientId client_id = MakeClientId(child_id, route_id);