Bug 1619953 - P2 - Asynchronous BlobURLDataRequest introduced r=baku

The content process should use this method to send blob url and triggering principal to the parent process and expect blobImpl in return, if the blob is found and the triggering principal subsumes the blob's principal.

Differential Revision: https://phabricator.services.mozilla.com/D75291

dom/ipc/ContentParent.cpp

@@ -6825,6 +6825,44 @@ PFileDescriptorSetParent* ContentParent::SendPFileDescriptorSetConstructor(
   return PContentParent::SendPFileDescriptorSetConstructor(aFD);
 }
 
+mozilla::ipc::IPCResult ContentParent::RecvBlobURLDataRequest(
+    const nsCString& aBlobURL, nsIPrincipal* pTriggeringPrincipal,
+    BlobURLDataRequestResolver&& aResolver) {
+  RefPtr<BlobImpl> blobImpl;
+  nsresult rv = NS_GetBlobForBlobURISpec(aBlobURL, getter_AddRefs(blobImpl));
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aResolver(rv);
+    return IPC_OK();
+  }
+
+  if (NS_WARN_IF(!blobImpl)) {
+    aResolver(NS_ERROR_DOM_BAD_URI);
+    return IPC_OK();
+  }
+
+  nsIPrincipal* const dataEntryPrincipal =
+      BlobURLProtocolHandler::GetDataEntryPrincipal(aBlobURL);
+
+  MOZ_ASSERT(dataEntryPrincipal);
+
+  if (!pTriggeringPrincipal->Subsumes(dataEntryPrincipal)) {
+    aResolver(NS_ERROR_DOM_BAD_URI);
+    return IPC_OK();
+  }
+
+  IPCBlob ipcBlob;
+  rv = IPCBlobUtils::Serialize(blobImpl, this, ipcBlob);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aResolver(rv);
+    return IPC_OK();
+  }
+
+  aResolver(ipcBlob);
+  return IPC_OK();
+}
+
 mozilla::ipc::IPCResult ContentParent::RecvReportServiceWorkerShutdownProgress(
     uint32_t aShutdownStateId, ServiceWorkerShutdownState::Progress aProgress) {
   RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();

dom/ipc/ContentParent.h

@@ -697,6 +697,10 @@ class ContentParent final
   PFileDescriptorSetParent* SendPFileDescriptorSetConstructor(
       const FileDescriptor& aFD) override;
 
+  mozilla::ipc::IPCResult RecvBlobURLDataRequest(
+      const nsCString& aBlobURL, nsIPrincipal* pTriggeringPrincipal,
+      BlobURLDataRequestResolver&& aResolver);
+
  protected:
   bool CheckBrowsingContextEmbedder(CanonicalBrowsingContext* aBC,
                                     const char* aOperation) const;

dom/ipc/PContent.ipdl

@@ -381,6 +381,12 @@ union SyncedContextInitializer
     WindowContextInitializer;
 };
 
+union BlobURLDataRequestResult
+{
+  IPCBlob;
+  nsresult;
+};
+
 /**
  * The PContent protocol is a top-level protocol between the UI process
  * and a content process. There is exactly one PContentParent/PContentChild pair
@@ -1658,6 +1664,8 @@ parent:
     async HistoryGo(MaybeDiscardedBrowsingContext aContext,
                     int32_t aOffset) returns(int32_t requestedIndex);
 
+    async BlobURLDataRequest(nsCString pBlobURL, nsIPrincipal pTriggeringPrincipal) returns (BlobURLDataRequestResult aResult);
+
 both:
     async ScriptError(nsString message, nsString sourceName, nsString sourceLine,
                       uint32_t lineNumber, uint32_t colNumber, uint32_t flags,