[Fetch][WIP] Support blob:, about:, and data: URLs.

LayoutTests/http/tests/fetch/script-tests/thorough/scheme-data.js

+if (self.importScripts) {
+  importScripts('/fetch/resources/fetch-test-helpers.js');
+  importScripts('/fetch/resources/thorough-util.js');
+}
+
+var url = "data:application/json,report({jsonpResult: 'success'});";
+
+var TEST_TARGETS = [
+// data: requests.
+  [BASE_URL + 'url=' + encodeURIComponent(url) + '&mode=same-origin&method=GET',
+   [fetchResolved, noContentLength, hasContentType, noServerHeader, hasBody, typeBasic],
+   [checkJsonpSuccess]],
+  [BASE_URL + 'url=' + encodeURIComponent(url) + '&mode=cors&method=GET',
+   [fetchResolved, noContentLength, hasContentType, noServerHeader, hasBody, typeBasic],
+   [checkJsonpSuccess]],
+  [BASE_URL + 'url=' + encodeURIComponent(url) + '&mode=no-cors&method=GET',
+   [fetchResolved, noContentLength, hasContentType, noServerHeader, hasBody, typeBasic],
+   [checkJsonpSuccess]],
+
+// data: requests with non-GET methods.
+  [BASE_URL + 'url=' + encodeURIComponent(url) + '&mode=same-origin&method=POST',
+   [fetchResolved, noContentLength, hasContentType, noServerHeader, hasBody, typeBasic],
+   [checkJsonpSuccess]],
+  [BASE_URL + 'url=' + encodeURIComponent(url) + '&mode=same-origin&method=HEAD',
+   [fetchResolved, noContentLength, hasContentType, noServerHeader, hasBody, typeBasic],
+   [checkJsonpSuccess]],
+
+// data: requests with same-origin redirects.
+  [REDIRECT_URL + encodeURIComponent(url) + '&mode=same-origin&method=GET',
+   [fetchRejected]],
+  [REDIRECT_URL + encodeURIComponent(url) + '&mode=cors&method=GET',
+   [fetchRejected]],
+
+// data: requests with cross-origin redirects.
+  [OTHER_REDIRECT_URL + encodeURIComponent(url) +
+   '&mode=same-origin&method=GET&ACAOrigin=*',
+   [fetchRejected]],
+  [OTHER_REDIRECT_URL + encodeURIComponent(url) +
+   '&mode=cors&method=GET&ACAOrigin=*',
+   [fetchRejected]],
+];
+
+if (self.importScripts) {
+  executeTests(TEST_TARGETS);
+  done();
+}