Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/resources/inspect-headers.py

Index: third_party/WebKit/LayoutTests/external/wpt/fetch/api/resources/inspect-headers.py
diff --git a/third_party/WebKit/LayoutTests/external/wpt/fetch/api/resources/inspect-headers.py b/third_party/WebKit/LayoutTests/external/wpt/fetch/api/resources/inspect-headers.py
new file mode 100644
index 0000000000000000000000000000000000000000..c4ace18ab64b11e9c09054c08be2d4d22f70264e
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/external/wpt/fetch/api/resources/inspect-headers.py
@@ -0,0 +1,22 @@
+def main(request, response):
+    headers = []
+    request_headers = []
+    if "headers" in request.GET:
+        checked_headers = request.GET.first("headers").split("|")
+        for header in checked_headers:
+          if header in request.headers:
+              headers.append(("x-request-" + header, request.headers.get(header, "") ))
+
+    if "cors" in request.GET:
+        if "Origin" in request.headers:
+            headers.append(("Access-Control-Allow-Origin", request.headers.get("Origin", "")))
+        else:
+            headers.append(("Access-Control-Allow-Origin", "*"))
+        headers.append(("Access-Control-Allow-Credentials", "true"))
+        headers.append(("Access-Control-Allow-Methods", "GET, POST, HEAD"))
+        exposed_headers = ["x-request-" + header for header in checked_headers]
+        headers.append(("Access-Control-Expose-Headers", ", ".join(exposed_headers)))
+        headers.append(("Access-Control-Allow-Headers", ", ".join(request.headers)))
+
+    headers.append(("content-type", "text/plain"))
+    return headers, ""