Send P2A json messages to the P3A endpoint.

These are handled with the same reporting software and privacy
protections on the server-side, so there's no value to maintaining
a separate endpoint for the P2A message type. Instead, send them
all to p3a-json.brave.com and sort into the approprate queue
on the back end.

Resolves brave/brave-browser#20478

components/p3a/brave_p3a_new_uploader.cc

@@ -71,25 +71,19 @@ net::NetworkTrafficAnnotationTag GetNetworkTrafficAnnotation(
 
 BraveP3ANewUploader::BraveP3ANewUploader(
     scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
-    const GURL& p3a_endpoint,
-    const GURL& p2a_endpoint)
-    : url_loader_factory_(url_loader_factory),
-      p3a_endpoint_(p3a_endpoint),
-      p2a_endpoint_(p2a_endpoint) {}
+    const GURL& p3a_endpoint)
+    : url_loader_factory_(url_loader_factory), p3a_endpoint_(p3a_endpoint) {}
 
 BraveP3ANewUploader::~BraveP3ANewUploader() = default;
 
 void BraveP3ANewUploader::UploadLog(const std::string& compressed_log_data,
                                     const std::string& upload_type) {
   auto resource_request = std::make_unique<network::ResourceRequest>();
-  if (upload_type == "p2a") {
-    resource_request->url = p2a_endpoint_;
-    resource_request->headers.SetHeader("X-Brave-P2A", "?1");
-    // TODO(issues/20478): Re-enable once backend is ready.
-    return;
-  } else if (upload_type == "p3a") {
-    resource_request->url = p3a_endpoint_;
+  resource_request->url = p3a_endpoint_;
+  if (upload_type == "p3a") {
     resource_request->headers.SetHeader("X-Brave-P3A", "?1");
+  } else if (upload_type == "p2a") {
+    resource_request->headers.SetHeader("X-Brave-P2A", "?1");
   } else {
     NOTREACHED();
   }

components/p3a/brave_p3a_new_uploader.h

@@ -27,8 +27,7 @@ class BraveP3ANewUploader {
  public:
   BraveP3ANewUploader(
       scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory,
-      const GURL& p3a_endpoint,
-      const GURL& p2a_endpoint);
+      const GURL& p3a_endpoint);
 
   BraveP3ANewUploader(const BraveP3ANewUploader&) = delete;
   BraveP3ANewUploader& operator=(const BraveP3ANewUploader&) = delete;
@@ -44,7 +43,6 @@ class BraveP3ANewUploader {
  private:
   scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory_;
   const GURL p3a_endpoint_;
-  const GURL p2a_endpoint_;
   std::unique_ptr<network::SimpleURLLoader> url_loader_;
 };
 

components/p3a/brave_p3a_service.cc

@@ -56,7 +56,6 @@ constexpr char kP3AServerUrl[] = "https://p3a.brave.com/";
 constexpr char kP2AServerUrl[] = "https://p2a.brave.com/";
 
 constexpr char kP3AJsonServerUrl[] = "https://p3a-json.brave.com/";
-constexpr char kP2AJsonServerUrl[] = "https://p2a-json.brave.com/";
 
 constexpr uint64_t kDefaultUploadIntervalSeconds = 60;  // 1 minute.
 
@@ -292,8 +291,8 @@ void BraveP3AService::Init(
       url_loader_factory, upload_server_url_, GURL(kP2AServerUrl),
       base::BindRepeating(&BraveP3AService::OnLogUploadComplete, this)));
 
-  new_uploader_.reset(new BraveP3ANewUploader(
-      url_loader_factory, GURL(kP3AJsonServerUrl), GURL(kP2AJsonServerUrl)));
+  new_uploader_.reset(
+      new BraveP3ANewUploader(url_loader_factory, GURL(kP3AJsonServerUrl)));
 
   upload_scheduler_.reset(new BraveP3AScheduler(
       base::BindRepeating(&BraveP3AService::StartScheduledUpload, this),