Move WebBlob.cpp from web/ -> core/exported/.

third_party/WebKit/Source/core/exported/BUILD.gn

Index: third_party/WebKit/Source/core/exported/BUILD.gn
diff --git a/third_party/WebKit/Source/core/exported/BUILD.gn b/third_party/WebKit/Source/core/exported/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..12a8e62e74746899386b2f2005c6bf6a6613b3b9
--- /dev/null
+++ b/third_party/WebKit/Source/core/exported/BUILD.gn
@@ -0,0 +1,10 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+import("//third_party/WebKit/Source/core/core.gni")
+
+blink_core_sources("exported") {
+  sources = [
+    "WebBlob.cpp",
+  ]
+}