Stop attaching a content type for beacon with ArrayBufferView

Bug: 1051439, 876671
Change-Id: Ie6055aa48fc27293a89fd20d4273654553fe85cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2060362Reviewed-by: Yoav Weiss <yoavweiss@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742069}

third_party/blink/common/features.cc

@@ -466,5 +466,11 @@ const base::Feature kCSSReducedFontLoadingInvalidations{
 const base::Feature kDiscardCodeCacheAfterFirstUse{
     "DiscardCodeCacheAfterFirstUse", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// The kill-switch for the fix for https://crbug.com/1051439.
+// TODO(crbug.com/1053369): Remove this around M84.
+const base::Feature kSuppressContentTypeForBeaconMadeWithArrayBufferView{
+    "SuppressContentTypeForBeaconMadeWithArrayBufferView",
+    base::FEATURE_ENABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace blink

third_party/blink/public/common/features.h

@@ -153,6 +153,9 @@ BLINK_COMMON_EXPORT extern const base::Feature
 
 BLINK_COMMON_EXPORT extern const base::Feature kDiscardCodeCacheAfterFirstUse;
 
+BLINK_COMMON_EXPORT extern const base::Feature
+    kSuppressContentTypeForBeaconMadeWithArrayBufferView;
+
 }  // namespace features
 }  // namespace blink
 

third_party/blink/renderer/core/loader/ping_loader.cc

@@ -31,6 +31,8 @@
 
 #include "third_party/blink/renderer/core/loader/ping_loader.h"
 
+#include "base/feature_list.h"
+#include "third_party/blink/public/common/features.h"
 #include "third_party/blink/public/platform/web_url_request.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/fileapi/file.h"
@@ -143,9 +145,12 @@ class BeaconDOMArrayBufferView final : public Beacon {
         base::checked_cast<wtf_size_t>(data_->byteLengthAsSizeT()));
     request.SetHttpBody(std::move(entity_body));
 
-    // FIXME: a reasonable choice, but not in the spec; should it give a
-    // default?
-    request.SetHTTPContentType(AtomicString("application/octet-stream"));
+    if (!base::FeatureList::IsEnabled(
+            features::kSuppressContentTypeForBeaconMadeWithArrayBufferView)) {
+      // FIXME: a reasonable choice, but not in the spec; should it give a
+      // default?
+      request.SetHTTPContentType(AtomicString("application/octet-stream"));
+    }
   }
 
   const AtomicString GetContentType() const override { return g_null_atom; }

third_party/blink/web_tests/external/wpt/beacon/headers/header-content-type-expected.txt

 This is a testharness.js-based test.
 PASS Test content-type header for a body string
-FAIL Test content-type header for a body ArrayBufferView assert_equals: Correct Content-Type header result expected "" but got "application/octet-stream"
+PASS Test content-type header for a body ArrayBufferView
 FAIL Test content-type header for a body ArrayBuffer assert_equals: Correct Content-Type header result expected "" but got "text/plain;charset=UTF-8"
 PASS Test content-type header for a body Blob
 PASS Test content-type header for a body FormData

third_party/blink/web_tests/http/tests/sendbeacon/beacon-same-origin-expected.txt

@@ -19,12 +19,11 @@ PASS
 Sending beacon with type: [object Uint32Array]
 PASS navigator.sendBeacon("resources/save-beacon.php?name=same-origin", payload); is true
 PASS Beacon sent successfully
-PASS Content-Type: application/octet-stream
 PASS Origin: http://127.0.0.1:8000
 PASS Referer: http://127.0.0.1:8000/sendbeacon/beacon-same-origin.html
 PASS Request-Method: POST
 PASS Length: 40
-PASS Body: QAAAAEEAAABCAAAAQwAAAEQAAABFAAAARgAAAEcAAABIAAAASQAAAA==
+PASS Body: @\0\0\0A\0\0\0B\0\0\0C\0\0\0D\0\0\0E\0\0\0F\0\0\0G\0\0\0H\0\0\0I
 PASS 
 Sending beacon with type: [object Blob]
 PASS navigator.sendBeacon("resources/save-beacon.php?name=same-origin", payload); is true