Use the fetchData helper function in more cases

- Extend the `fetchData` helper function to also support fetching of "blob" data.

 - Use the `fetchData` helper function more in the code-base, when fetching non-PDF data. Given that the Fetch API isn't supported for all protocols, this should improve compatibility for the PDF.js library.

src/display/display_utils.js

@@ -399,6 +399,8 @@ async function fetchData(url, type = "text") {
     switch (type) {
       case "arraybuffer":
         return response.arrayBuffer();
+      case "blob":
+        return response.blob();
       case "json":
         return response.json();
     }
@@ -419,6 +421,7 @@ async function fetchData(url, type = "text") {
         let data;
         switch (type) {
           case "arraybuffer":
+          case "blob":
           case "json":
             data = request.response;
             break;

src/display/editor/tools.js

@@ -27,7 +27,12 @@ import {
   Util,
   warn,
 } from "../../shared/util.js";
-import { getColorValues, getRGB, PixelsPerInch } from "../display_utils.js";
+import {
+  fetchData,
+  getColorValues,
+  getRGB,
+  PixelsPerInch,
+} from "../display_utils.js";
 
 function bindEvents(obj, element, names) {
   for (const name of names) {
@@ -116,12 +121,7 @@ class ImageManager {
       let image;
       if (typeof rawData === "string") {
         data.url = rawData;
-
-        const response = await fetch(rawData);
-        if (!response.ok) {
-          throw new Error(response.statusText);
-        }
-        image = await response.blob();
+        image = await fetchData(rawData, "blob");
       } else {
         image = data.file = rawData;
       }