Use in-class initializers for base::WeakPtrFactory in extensions/.

Generated by: https://chromium-review.googlesource.com/c/chromium/src/+/1689216

Bug: 981415
Change-Id: I6fefa72e30af31205eb9657a2ed932b8eec90c39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1698637
Reviewed-by: Devlin <[email protected]>
Commit-Queue: Jeremy Roman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#676880}
diff --git a/extensions/renderer/script_injection.cc b/extensions/renderer/script_injection.cc
index c54f9ea..5b36db98 100644
--- a/extensions/renderer/script_injection.cc
+++ b/extensions/renderer/script_injection.cc
@@ -167,8 +167,7 @@
       complete_(false),
       did_inject_js_(false),
       log_activity_(log_activity),
-      frame_watcher_(new FrameWatcher(render_frame, this)),
-      weak_ptr_factory_(this) {
+      frame_watcher_(new FrameWatcher(render_frame, this)) {
   CHECK(injection_host_.get());
 }