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

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

Some existing uses of NULL are replaced with nullptr to remove
presubmit errors.

Bug: 981415
Change-Id: I9824a00bd16e27cf2f0e03e6c7127ffc457b56e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1697372
Commit-Queue: Jeremy Roman <[email protected]>
Reviewed-by: Lei Zhang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#676912}
diff --git a/chrome/browser/extensions/blacklist_check.cc b/chrome/browser/extensions/blacklist_check.cc
index cf55f8c..a3ec2250 100644
--- a/chrome/browser/extensions/blacklist_check.cc
+++ b/chrome/browser/extensions/blacklist_check.cc
@@ -12,7 +12,7 @@
 
 BlacklistCheck::BlacklistCheck(Blacklist* blacklist,
                                scoped_refptr<const Extension> extension)
-    : PreloadCheck(extension), blacklist_(blacklist), weak_ptr_factory_(this) {}
+    : PreloadCheck(extension), blacklist_(blacklist) {}
 
 BlacklistCheck::~BlacklistCheck() {}