[wip] Add some more state to RenderViewHost's lifetime.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index ad30ee73edca301b794d6b96c75f2a5cd8bfe95c..9bef35c6f8d17de9143de5ca47d01a01d7346301 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -214,6 +214,7 @@ RenderViewHostImpl::RenderViewHostImpl(
       sudden_termination_allowed_(false),
       render_view_termination_status_(base::TERMINATION_STATUS_STILL_RUNNING),
       virtual_keyboard_requested_(false),
+      copy_requests_(0),
       weak_factory_(this) {
   DCHECK(instance_.get());
   CHECK(delegate_);  // http://crbug.com/82827
@@ -736,7 +737,8 @@ void RenderViewHostImpl::OnSwappedOut(bool timed_out) {
       break;
     case STATE_PENDING_SHUTDOWN:
       DCHECK(!pending_shutdown_on_swap_out_.is_null());
-      pending_shutdown_on_swap_out_.Run();
+      if (copy_requests_ == 0)
+        pending_shutdown_on_swap_out_.Run();
       break;
     default:
       NOTREACHED();
@@ -745,7 +747,8 @@ void RenderViewHostImpl::OnSwappedOut(bool timed_out) {
 
 void RenderViewHostImpl::WasSwappedOut(
     const base::Closure& pending_delete_on_swap_out) {
-  Send(new ViewMsg_WasSwappedOut(GetRoutingID()));
+  if (copy_requests_ == 0)
+    Send(new ViewMsg_WasSwappedOut(GetRoutingID()));
   if (rvh_state_ == STATE_WAITING_FOR_UNLOAD_ACK) {
     if (instance_->active_view_count())
       SetState(STATE_PENDING_SWAP_OUT);
@@ -1859,6 +1862,43 @@ void RenderViewHostImpl::GetAudioOutputControllers(
   audio_host->GetOutputControllers(GetRoutingID(), callback);
 }
 
+void RenderViewHostImpl::CopyFromBackingStoreCallback(
+    const base::Callback<void(bool, const SkBitmap&)>& callback,
+    bool success,
+    const SkBitmap& bitmap) {
+  --copy_requests_;
+  LOG(ERROR) << "Done with a request: " << copy_requests_;
+  callback.Run(success, bitmap);
+  if (copy_requests_ == 0) {
+    if (!IsRVHStateActive(rvh_state_)) {
+      Send(new ViewMsg_WasSwappedOut(GetRoutingID()));
+      instance_->decrement_active_view_count();
+    }
+
+    if (rvh_state_ == STATE_PENDING_SHUTDOWN) {
+      DCHECK(!pending_shutdown_on_swap_out_.is_null());
+      pending_shutdown_on_swap_out_.Run();

[mfomitchev, 2014/03/24 18:49:10]

Can't we have a situation where this gets executed before
RenderViewHostImpl::OnSwappedOut()? If that happens,
pending_shutdown_on_swap_out_ will be executed twice..

+    }
+  }
+}
+
+void RenderViewHostImpl::CopyFromBackingStore(
+    const gfx::Rect& src_rect,
+    const gfx::Size& accelerated_dst_size,
+    const base::Callback<void(bool, const SkBitmap&)>& callback) {
+  DCHECK(IsRVHStateActive(rvh_state_));
+  if (!IsRVHStateActive(rvh_state_)) {
+    callback.Run(false, SkBitmap());
+    return;
+  }
+  ++copy_requests_;
+  LOG(ERROR) << "Starting a request: " << copy_requests_;
+  RenderWidgetHostImpl::CopyFromBackingStore(src_rect, accelerated_dst_size,
+      base::Bind(&RenderViewHostImpl::CopyFromBackingStoreCallback,
+                 weak_factory_.GetWeakPtr(),
+                 callback));
+}
+
 void RenderViewHostImpl::ClearFocusedNode() {
   Send(new ViewMsg_ClearFocusedNode(GetRoutingID()));
 }
@@ -2049,7 +2089,8 @@ void RenderViewHostImpl::SetState(RenderViewHostImplState rvh_state) {
   // swapped out status of this RenderView gets flipped to/from live.
   if (!IsRVHStateActive(rvh_state_) && IsRVHStateActive(rvh_state))
     instance_->increment_active_view_count();
-  else if (IsRVHStateActive(rvh_state_) && !IsRVHStateActive(rvh_state))
+  else if (IsRVHStateActive(rvh_state_) && !IsRVHStateActive(rvh_state) &&
+           copy_requests_ == 0)

[clamy, 2014/02/26 16:50:56]

If the site instance is not decremented when the new page commits (ie when
WasSwappedOut is called), then the RVH will not go into state PENDING_SHUTDOWN.
Its associated RFH will be stored in the map of swapped out hosts in the
RenderFrameHostManager. When the swap out ack is received, the state will just
be set to SWAPPED_OUT, and the RFH and RVH will not be deleted as they should
be.

     instance_->decrement_active_view_count();
 
   // Whenever we change the RVH state to and from live or swapped out state, we