Adding drawable to CRD andorid and iOS gl rendering pipeline.

remoting/client/display/gl_cursor.cc

Index: remoting/client/display/gl_cursor.cc
diff --git a/remoting/client/display/gl_cursor.cc b/remoting/client/display/gl_cursor.cc
index 4a4c55a1824ef50cd2cb5fd971ef1b4ba6271a49..1668bda9e9129139c39e4c4b48bf8b8b8a433229 100644
--- a/remoting/client/display/gl_cursor.cc
+++ b/remoting/client/display/gl_cursor.cc
@@ -18,7 +18,9 @@ namespace {
 const int kDefaultCursorDataSize = 32 * 32 * GlRenderLayer::kBytesPerPixel;
 }  // namespace
 
-GlCursor::GlCursor() {}
+GlCursor::GlCursor() : weak_factory_(this) {
+  SetZIndex(DrawableZIndex::CURSOR);
+}
 
 GlCursor::~GlCursor() {}
 
@@ -68,7 +70,7 @@ void GlCursor::SetCursorVisible(bool visible) {
   visible_ = visible;
 }
 
-void GlCursor::SetCanvas(GlCanvas* canvas) {
+void GlCursor::SetCanvas(Canvas* canvas) {
   if (!canvas) {
     layer_.reset();
     return;
@@ -80,10 +82,11 @@ void GlCursor::SetCanvas(GlCanvas* canvas) {
   SetCursorPosition(cursor_x_, cursor_y_);
 }
 
-void GlCursor::Draw() {
+bool GlCursor::Draw() {
   if (layer_ && current_cursor_data_ && visible_) {
     layer_->Draw(1.f);
   }
+  return false;
 }
 
 void GlCursor::SetCurrentCursorShape(bool size_changed) {
@@ -98,4 +101,8 @@ void GlCursor::SetCurrentCursorShape(bool size_changed) {
   }
 }
 
+base::WeakPtr<Drawable> GlCursor::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();

[joedow, 2017/01/10 00:19:44]

Maybe I missed the conclusion of this discussion from the CL that was superseded
by this one, but I had thought this was dangerous as the affinity of the WeakPtr
would be bound to the first thread which called this method and that it was
safer to store a WeakPtr member which was initialized on the correct thread and
had references passed out.

[nicholss, 2017/01/10 16:58:34]

That was not for this class.

[joedow, 2017/01/10 18:49:27]

I thought it was for all classes which expose a WeakPtr.  The problem as I
understand it that the first time you call GetWeakPtr() the underlying thread
affinity for the factory and weakptr are set.  If someone doesn't call this
method as expected (i.e. on a different thread) then you will have a problem.

One approach would be to use a thread checker and DCHECK that each access to
this method occurs on the thread which created the factory.  Then you should be
ok.

[Yuwei, 2017/01/10 19:36:10]

As discussed offline, these Drawables are supposed to be only used on the
display thread so I just didn't bother introducing the thread checker. I think
it's good to introduce a thread checker just to be safer, since none of these
functions will work on a non-display thread.

[nicholss, 2017/01/10 21:43:10]

Acknowledged.

+}
+
 }  // namespace remoting