Call Pepper's Flush command properly

Need to provide a flag to the Flush command otherwise it won't return
a proper error to notify that Flush has failed. Because of this there's
some content in the plugin area not updated until the next frame
arrives.

BUG=80000, 91300
TEST=Try chromoting, do a small action, stop the mouse, animation should completes.

Review URL: http://codereview.chromium.org/7550008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95227 0039d316-1c4b-4281-b951-d872f2087c98

remoting/client/chromoting_client.cc

@@ -107,6 +107,14 @@ void ChromotingClient::ProcessVideoPacket(const VideoPacket* packet,
     return;
   }
 
+  // If the video packet is empty then drop it. Empty packets are used to
+  // maintain activity on the network.
+  if (!packet->has_data() || packet->data().size() == 0) {
+    done->Run();
+    delete done;
+    return;
+  }
+
   // Record size of the packet for statistics.
   stats_.video_bandwidth()->Record(packet->data().size());
 

remoting/client/plugin/pepper_view.cc

@@ -23,7 +23,7 @@ namespace remoting {
 PepperView::PepperView(ChromotingInstance* instance, ClientContext* context)
   : instance_(instance),
     context_(context),
-    pending_flush_(false),
+    flush_blocked_(false),
     is_static_fill_(false),
     static_fill_color_(0),
     ALLOW_THIS_IN_INITIALIZER_LIST(task_factory_(this)) {
@@ -164,20 +164,34 @@ void PepperView::BlankRect(pp::ImageData& image_data, const pp::Rect& rect) {
 }
 
 void PepperView::FlushGraphics(base::Time paint_start) {
-  int error = graphics2d_.Flush(
-      TaskToCompletionCallback(
-          task_factory_.NewRunnableMethod(&PepperView::OnPaintDone,
-                                          paint_start)));
+  scoped_ptr<Task> task(
+      task_factory_.NewRunnableMethod(&PepperView::OnPaintDone, paint_start));
+
+  // Flag needs to be set here in order to get a proper error code for Flush().
+  // Otherwise Flush() will always return PP_OK_COMPLETIONPENDING and the error
+  // would be hidden.
+  //
+  // Note that we can also handle this by providing an actual callback which
+  // takes the result code. Right now everything goes to the task that doesn't
+  // result value.
+  pp::CompletionCallback pp_callback(&CompletionCallbackTaskAdapter,
+                                     task.get(),
+                                     PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+  int error = graphics2d_.Flush(pp_callback);
 
   // There is already a flush in progress so set this flag to true so that we
   // can flush again later.
   // |paint_start| is then discarded but this is fine because we're not aiming
   // for precise measurement of timing, otherwise we need to keep a list of
   // queued start time(s).
   if (error == PP_ERROR_INPROGRESS)
-    pending_flush_ = true;
+    flush_blocked_ = true;
   else
-    pending_flush_ = false;
+    flush_blocked_ = false;
+
+  // If Flush() returns asynchronously then release the task.
+  if (error == PP_OK_COMPLETIONPENDING)
+    ignore_result(task.release());
 }
 
 void PepperView::SetSolidFill(uint32 color) {
@@ -326,7 +340,7 @@ void PepperView::OnPaintDone(base::Time paint_start) {
 
   // If the last flush failed because there was already another one in progress
   // then we perform the flush now.
-  if (pending_flush_)
+  if (flush_blocked_)
     FlushGraphics(base::Time::Now());
   return;
 }

remoting/client/plugin/pepper_view.h

@@ -96,7 +96,7 @@ class PepperView : public ChromotingView,
 
   // True if there is pending paint commands in Pepper's queue. This is set to
   // true if the last flush returns a PP_ERROR_INPROGRESS error.
-  bool pending_flush_;
+  bool flush_blocked_;
 
   // The size of the plugin element.
   gfx::Size plugin_size_;