Remove default textures in (!bind_generates_resource) context groups.

gpu/command_buffer/service/texture_manager.h

Index: gpu/command_buffer/service/texture_manager.h
diff --git a/gpu/command_buffer/service/texture_manager.h b/gpu/command_buffer/service/texture_manager.h
index 214122eccc4641cc8e595f078edd7dfd4ab5639f..ced56bb217d24605fabef1a543cfe46c0c4d5020 100644
--- a/gpu/command_buffer/service/texture_manager.h
+++ b/gpu/command_buffer/service/texture_manager.h
@@ -488,6 +488,10 @@ class GPU_EXPORT TextureManager {
     framebuffer_manager_ = manager;
   }
 
+  void set_use_default_textures(bool use_default_textures) {
+    use_default_textures_ = use_default_textures;
+  }
+
   // Init the texture manager.
   bool Initialize();
 
@@ -774,6 +778,8 @@ class GPU_EXPORT TextureManager {
   GLint max_levels_;
   GLint max_cube_map_levels_;
 
+  bool use_default_textures_;
+
   int num_unrenderable_textures_;
   int num_unsafe_textures_;
   int num_uncleared_mips_;