bitmap_uploader: delete dead code

As I was inspecting cc/surfaces clients, I noticed some dead code in
bitmap_uploader. This CL deletes it.

BUG=none

Review-Url: https://codereview.chromium.org/2165253002
Cr-Commit-Position: refs/heads/master@{#406873}

services/ui/public/cpp/bitmap_uploader.h

@@ -78,7 +78,6 @@ class BitmapUploader : public WindowSurfaceClient {
   Format format_;
   std::unique_ptr<std::vector<unsigned char>> bitmap_;
   uint32_t next_resource_id_;
-  uint32_t id_namespace_;
   base::hash_map<uint32_t, uint32_t> resource_to_texture_id_map_;
 
   DISALLOW_COPY_AND_ASSIGN(BitmapUploader);

services/ui/public/cpp/lib/bitmap_uploader.cc

@@ -33,8 +33,7 @@ BitmapUploader::BitmapUploader(Window* window)
       width_(0),
       height_(0),
       format_(BGRA),
-      next_resource_id_(1u),
-      id_namespace_(0u) {}
+      next_resource_id_(1u) {}
 
 BitmapUploader::~BitmapUploader() {
 }
@@ -185,12 +184,6 @@ uint32_t BitmapUploader::BindTextureForSize(const gfx::Size& size) {
   return texture;
 }
 
-void BitmapUploader::SetIdNamespace(uint32_t id_namespace) {
-  id_namespace_ = id_namespace;
-  if (color_ != g_transparent_color || bitmap_.get())
-    Upload();
-}
-
 void BitmapUploader::OnResourcesReturned(
     WindowSurface* surface,
     mojo::Array<cc::ReturnedResource> resources) {