Social media options being ignored 0.67.x and above until toggled

[bbondy]

Description

Recent refactoring creates a new instance of the adblock engine and so it doesn't preserve the tags which were set on startup.

template<typename T>
LoadDATFileDataResult<T> LoadDATFileData(
    const base::FilePath& dat_file_path) {
  DATFileDataBuffer buffer;
  GetDATFileData(dat_file_path, &buffer);
  std::unique_ptr<T> client;  
  client = std::make_unique<T>();  <------ Problem

On startup the tags are not applied.
However if you go into settings and manually toggle them it worked.

Steps to Reproduce

1. Start Brave
2. Load Load https://fmarier.github.io/brave-testing/social-widgets.html

Actual result:

Things like Facebook are not loaded

Expected result:

Things like Facebook should be loaded

Reproduces how often:

Always 0.67.x and 0.68.x

Brave version (brave://version info)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the dev channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

[btlechowski]

Verification passed on

Brave	0.67.110 Chromium: 75.0.3770.100 (Official Build) beta(64-bit)
Revision	cd0b15c8b6a4e70c44e27f35c37a4029bad3e3b0-refs/branch-heads/3770@{#1033}
OS	Ubuntu 18.04 LTS

Verified steps from the description.

Reproduced the issue on 0.67.79

Verified that is fixed:

Verification passed on

Brave	0.67.111 Chromium: 75.0.3770.100 (Official Build) beta (64-bit)
Revision	cd0b15c8b6a4e70c44e27f35c37a4029bad3e3b0-refs/branch-heads/3770@{#1033}
OS	Windows 10 OS Version 1803 (Build 17134.523)

• Verified the STR from the description

Verified passed with

Brave	0.67.112 Chromium: 76.0.3809.62 (Official Build) beta (64-bit)
Revision	7b77856b3aa34d72f246d12340fc1ded8b2c0e83-refs/branch-heads/3809@{#798}
OS	Mac OS X

• Reproduced the issue on Dev channel with 0.67.79
• Verified STR from description