Remove WebURLResponse::ResourceResponseContainer

It's needed to workaround the DISALLOW_NEW_EXCEPT_PLACEMENT_NEW
annotation for ResourceResponse, which is unproductive.

This CL also adds some const qualifiers to express invariants.

Bug: 570946
Change-Id: I05a13178253b66267ea91652f2f32636df98cbbb
Reviewed-on: https://chromium-review.googlesource.com/1122142Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572023}

third_party/blink/public/platform/web_url_response.h

@@ -305,15 +305,13 @@ class WebURLResponse {
 #endif
 
  private:
-  struct ResourceResponseContainer;
-
   // If this instance owns a ResourceResponse then |owned_resource_response_|
   // is non-null and |resource_response_| points to the ResourceResponse
   // instance it contains.
-  std::unique_ptr<ResourceResponseContainer> owned_resource_response_;
+  const std::unique_ptr<ResourceResponse> owned_resource_response_;
 
   // Should never be null.
-  ResourceResponse* resource_response_;
+  ResourceResponse* const resource_response_;
 };
 
 }  // namespace blink

third_party/blink/renderer/platform/exported/web_url_response.cc

@@ -70,28 +70,16 @@ class URLResponseExtraDataContainer : public ResourceResponse::ExtraData {
 
 }  // namespace
 
-// The purpose of this struct is to permit allocating a ResourceResponse on the
-// heap, which is otherwise disallowed by the DISALLOW_NEW_EXCEPT_PLACEMENT_NEW
-// annotation on ResourceResponse.
-struct WebURLResponse::ResourceResponseContainer {
-  ResourceResponseContainer() = default;
-
-  explicit ResourceResponseContainer(const ResourceResponse& r)
-      : resource_response(r) {}
-
-  ResourceResponse resource_response;
-};
-
 WebURLResponse::~WebURLResponse() = default;
 
 WebURLResponse::WebURLResponse()
-    : owned_resource_response_(new ResourceResponseContainer()),
-      resource_response_(&owned_resource_response_->resource_response) {}
+    : owned_resource_response_(std::make_unique<ResourceResponse>()),
+      resource_response_(owned_resource_response_.get()) {}
 
 WebURLResponse::WebURLResponse(const WebURLResponse& r)
     : owned_resource_response_(
-          new ResourceResponseContainer(*r.resource_response_)),
-      resource_response_(&owned_resource_response_->resource_response) {}
+          std::make_unique<ResourceResponse>(*r.resource_response_)),
+      resource_response_(owned_resource_response_.get()) {}
 
 WebURLResponse::WebURLResponse(const WebURL& url) : WebURLResponse() {
   SetURL(url);

third_party/blink/renderer/platform/loader/fetch/resource_response.h

@@ -61,8 +61,6 @@ struct CrossThreadResourceResponseData;
 // member variable to this class, do not forget to add the corresponding
 // one in CrossThreadResourceResponseData and write copying logic.
 class PLATFORM_EXPORT ResourceResponse final {
-  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-
  public:
   enum HTTPVersion : uint8_t {
     kHTTPVersionUnknown,