[Fetch] Expose Fetch API to window/workers without flags

LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt

Index: LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt
diff --git a/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt b/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt
index f33e36cc88fcdcfa80da0ba60be08a383c88c10d..2e6867ae7410504e202fbcdb130e580fd91a00c1 100644
--- a/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt
+++ b/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt
@@ -922,6 +922,18 @@ interface HTMLVideoElement
 interface HashChangeEvent
     method constructor
     method initHashChangeEvent
+interface Headers
+    method append
+    method constructor
+    method delete
+    method entries
+    method forEach
+    method get
+    method getAll
+    method has
+    method keys
+    method set
+    method values
 interface History
     method back
     method constructor
@@ -1400,6 +1412,20 @@ interface RegExp
     method exec
     method test
     method toString
+interface Request
+    method arrayBuffer
+    method blob
+    method clone
+    method constructor
+    method json
+    method text
+interface Response
+    method arrayBuffer
+    method blob
+    method clone
+    method constructor
+    method json
+    method text
 interface SVGAElement
     method constructor
 interface SVGAngle
@@ -2785,6 +2811,7 @@ interface Window
     method close
     method confirm
     method constructor
+    method fetch
     method find
     method focus
     method getComputedStyle