Hook up BeginFrameSource to SurfaceFactoryClient via SurfaceManager

cc/surfaces/surface_manager.h

Index: cc/surfaces/surface_manager.h
diff --git a/cc/surfaces/surface_manager.h b/cc/surfaces/surface_manager.h
index a3f7b9b19ff8cc0b466fac599d13499c9ff4d3bd..d756baae7620746461746a77b589949d8bbf015a 100644
--- a/cc/surfaces/surface_manager.h
+++ b/cc/surfaces/surface_manager.h
@@ -21,8 +21,10 @@
 #include "cc/surfaces/surfaces_export.h"
 
 namespace cc {
+class BeginFrameSource;
 class CompositorFrame;
 class Surface;
+class SurfaceFactoryClient;
 
 class CC_SURFACES_EXPORT SurfaceManager {
  public:
@@ -58,7 +60,43 @@ class CC_SURFACES_EXPORT SurfaceManager {
   // possibly because a renderer process has crashed.
   void InvalidateSurfaceIdNamespace(uint32_t id_namespace);
 
+  // SurfaceFactoryClient and namespace hierarchy may be registered in
+  // either order. (The relationship to between ui::Compositor /
+  // DelegatedFrameHost is known before ui::Compositor has a surface/client).
+  // However, DelegatedFrameHost can register itself as a client before
+  // its relationship with the ui::Compositor is known.)
+  //
+  // SurfaceFactoryClient registration for a namespace should outlive
+  // the BeginFrameSource registration.
+  //
+  // Associates a SurfaceFactoryClient with the surface id namespace it uses.
+  // SurfaceFactoryClient and surface namespaces/allocators have a 1:1 mapping.
+  // A nullptr client implies unregistering the client from the namespace.
+  // Caller guarantees the client is alive between register/unregister.
+  // Reregistering the same namespace when a previous client is active is not
+  // valid.
+  void RegisterSurfaceFactoryClient(uint32_t id_namespace,

[brianderson, 2016/02/18 23:01:07]

Is it possible to fold this into RegisterSurfaceIdNamespace? Or will the
SurfaceFactoryClient not always be known by that point?

[enne (OOO), 2016/02/19 21:26:57]

Sadly, no.  SurfaceIdNamespace is about the allocator, which does not have the
same lifetime as the SurfaceFactoryClient.  I thought about refactoring this so
that surface factories owned their allocators and this could be combined.  To
that end, I talked about this with jbauman some, who said that there were goals
of moving the allocator off even farther away than it is now, so I think it's
important to keep them decoupled to enable that future refactoring.

+                                    SurfaceFactoryClient* client);
+
+  void RegisterBeginFrameSource(BeginFrameSource* source,
+                                uint32_t id_namespace);
+  void UnregisterBeginFrameSource(BeginFrameSource* source);
+
+  // TODO(enne): Call this in the right spots.
+  // Children should always register/unregister with their parents.
+  // Unregistration of child namespaces should happen before
+  // unregistering surface factory clients.
+  void RegisterSurfaceNamespaceHierarchy(uint32_t parent_namespace,
+                                         uint32_t child_namespace);
+  void UnregisterSurfaceNamespaceHierarchy(uint32_t parent_namespace,
+                                           uint32_t child_namespace);
+
  private:
+  void RecursivelyAttachBeginFrameSource(uint32_t id_namespace,
+                                         BeginFrameSource* source);
+  void RecursivelyDetachBeginFrameSource(uint32_t id_namespace,
+                                         BeginFrameSource* source);
+
   void GarbageCollectSurfaces();
 
   using SurfaceMap = std::unordered_map<SurfaceId, Surface*, SurfaceIdHash>;
@@ -80,6 +118,25 @@ class CC_SURFACES_EXPORT SurfaceManager {
   // satisfied.
   std::unordered_set<uint32_t> valid_surface_id_namespaces_;
 
+  // Begin frame source routing. Both BeginFrameSource and SurfaceFactoryClient
+  // pointers guaranteed alive by callers until unregistered.
+  struct ClientSourceMapping {
+    ClientSourceMapping();
+    ~ClientSourceMapping();
+    bool is_empty() const { return !client && !children.size(); }
+    // The client that's responsible for creating this namespace.  Never null.
+    SurfaceFactoryClient* client;
+    // The currently assigned begin frame source for this client.
+    BeginFrameSource* source;
+    // This represents a dag of parent -> children mapping.
+    std::vector<uint32_t> children;
+  };
+  std::unordered_map<uint32_t, ClientSourceMapping> namespace_client_map_;
+  // Set of which sources are registered to which namespace.  Any child
+  // that is implicitly using this namespace must be reachable by the
+  // parent in the dag.
+  std::unordered_map<BeginFrameSource*, uint32_t> registered_sources_;
+
   DISALLOW_COPY_AND_ASSIGN(SurfaceManager);
 };