Add FetchDataConsumerHandle and utility functions/classes

Source/modules/modules.gypi

Index: Source/modules/modules.gypi
diff --git a/Source/modules/modules.gypi b/Source/modules/modules.gypi
index 7b1bb372def7a60c24c45b3384be86ff51993f8b..f0d506faddf9424b2b9545ccd1b016e898ddb825 100644
--- a/Source/modules/modules.gypi
+++ b/Source/modules/modules.gypi
@@ -736,10 +736,13 @@
       'encryptedmedia/SimpleContentDecryptionModuleResultPromise.h',
       'fetch/CompositeDataConsumerHandle.cpp',
       'fetch/CompositeDataConsumerHandle.h',
+      'fetch/DataConsumerHandleUtil.cpp',
+      'fetch/DataConsumerHandleUtil.h',
       'fetch/Body.cpp',
       'fetch/Body.h',
       'fetch/BodyStreamBuffer.cpp',
       'fetch/BodyStreamBuffer.h',
+      'fetch/FetchDataConsumerHandle.h',
       'fetch/FetchHeaderList.cpp',
       'fetch/FetchHeaderList.h',
       'fetch/FetchManager.cpp',
@@ -1451,6 +1454,8 @@
       'compositorworker/CompositorWorkerManagerTest.cpp',
       'fetch/BodyStreamBufferTest.cpp',
       'fetch/CompositeDataConsumerHandleTest.cpp',
+      'fetch/DataConsumerHandleTestUtil.h',
+      'fetch/DataConsumerHandleUtilTest.cpp',
       'fetch/FetchResponseDataTest.cpp',
       'fetch/RequestTest.cpp',
       'fetch/ResponseTest.cpp',