Fix ScreenshotCoordinator trying to install non-existant module

When image_editor DFM is not defined, pressing the edit button should do
nothing rather than crash chrome.

Bug: 1145044
Change-Id: Ideaf738bde7c626bee627648c517f4fe9f3a4910
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2517619Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Mohamed Heikal <mheikal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823671}

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/screenshot/ScreenshotCoordinator.java

@@ -140,6 +140,10 @@ public class ScreenshotCoordinator {
      * @param onSuccess. Runnable to run on success.
      */
     protected void retryInstallEditor(Runnable onSuccess) {
+        if (mImageEditorModuleProvider == null) {
+            // If the module does not exist, nothing to do.
+            return;
+        }
         installEditor(false, onSuccess);
     }