Bug 1208661 - Move Dump() up from ContentClient to CompositableClient. r=BenWa

Only some ContentClient implementations implement it, but it allows it to be
called from more general code. Other CompositableClient implementations can
be provided later.

--HG--
extra : rebase_source : ae8cee4501bc6c1fa00809b7e6fdc4a98da66b40
extra : source : 70568b823d6ecf1b50c18d5712556a89ef954b12

gfx/layers/client/CompositableClient.h

@@ -127,6 +127,10 @@ public:
 
   explicit CompositableClient(CompositableForwarder* aForwarder, TextureFlags aFlags = TextureFlags::NO_FLAGS);
 
+  virtual void Dump(std::stringstream& aStream,
+                    const char* aPrefix="",
+                    bool aDumpHtml=false) {};
+
   virtual TextureInfo GetTextureInfo() const = 0;
 
   LayersBackend GetCompositorBackendType() const;

gfx/layers/client/ContentClient.h

@@ -88,10 +88,6 @@ public:
 
   virtual void PrintInfo(std::stringstream& aStream, const char* aPrefix);
 
-  virtual void Dump(std::stringstream& aStream,
-                    const char* aPrefix="",
-                    bool aDumpHtml=false) {};
-
   virtual void Clear() = 0;
   virtual RotatedContentBuffer::PaintState BeginPaintBuffer(PaintedLayer* aLayer,
                                                             uint32_t aFlags) = 0;