cc: Delete the RendererClient class.

cc/output/gl_renderer.h

Index: cc/output/gl_renderer.h
diff --git a/cc/output/gl_renderer.h b/cc/output/gl_renderer.h
index 87554d02f35aa67ef41fd3f15ea6c0ee459f42c0..3e1203068c7d6008f29a9744f9c2c93071712409 100644
--- a/cc/output/gl_renderer.h
+++ b/cc/output/gl_renderer.h
@@ -51,8 +51,7 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
  public:
   class ScopedUseGrContext;
 
-  GLRenderer(RendererClient* client,
-             const RendererSettings* settings,
+  GLRenderer(const RendererSettings* settings,
              OutputSurface* output_surface,
              ResourceProvider* resource_provider,
              TextureMailboxDeleter* texture_mailbox_deleter,
@@ -72,8 +71,6 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
  protected:
   void DidChangeVisibility() override;
 
-  bool IsBackbufferDiscarded() const { return is_backbuffer_discarded_; }
-
   const gfx::QuadF& SharedGeometryQuad() const { return shared_geometry_quad_; }
   const StaticGeometryBinding* SharedGeometry() const {
     return shared_geometry_.get();
@@ -252,9 +249,6 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
   void ReinitializeGLState();
   void RestoreGLState();
 
-  void DiscardBackbuffer() override;
-  void EnsureBackbuffer() override;
-
   void ScheduleCALayers(DrawingFrame* frame);
   void ScheduleOverlays(DrawingFrame* frame);
 
@@ -505,7 +499,6 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
 
   gfx::Rect swap_buffer_rect_;
   gfx::Rect scissor_rect_;
-  bool is_backbuffer_discarded_;
   bool is_using_bind_uniform_;
   bool is_scissor_enabled_;
   bool scissor_rect_needs_reset_;