Reload active tab when widevine library is ready to use (uplift to 1.7.x)

[bsclifton]

Uplift of #4978
Fixes brave/brave-browser#4646

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[bsclifton]

redo of #5049 after discussion on Slack:
https://bravesoftware.slack.com/archives/CHGKGMHDJ/p1585160096007100

[bsclifton]

Related (reported when testing this issue) - Netflix does not work due to Widevine Content Decryption Module error in brave://components

[kjozwiak]

Restarting macOS as test-browser failed as per https://ci.brave.com/job/brave-browser-build-pr/job/pr4978_issue_4646_widevine_1.7.x/3/execution/node/494/log/

14:28:39  [508/508] BraveRewardsBrowserTest.TipConnectedPublisherAnonAndConnected (TIMED OUT)
14:28:39  1 test timed out:
14:28:39      BraveRewardsBrowserTest.TipConnectedPublisherAnonAndConnected (../../brave/components/brave_rewards/browser/rewards_service_browsertest.cc:2762)

Even though the above isn't related to Widevine, restarting just in case to make sure the above failure is intermittent.

[kjozwiak]

Travis is failing TEST_SUITE=test-security due to the minimist npm package being vulnerable. It's a known issue as per brave/brave-browser#8722 and doesn't block the PR from being uplifted.

[kjozwiak]

Looks like it timed out as per the following:

19:53:45  [507/507] BraveRewardsBrowserTest.TipConnectedPublisherAnonAndConnected (TIMED OUT)
19:53:45  1 test timed out:
19:53:45      BraveRewardsBrowserTest.TipConnectedPublisherAnonAndConnected (../../brave/components/brave_rewards/browser/rewards_service_browsertest.cc:2762)

@bsclifton created brave/brave-browser#8881 to address the above timeout.

[kjozwiak]

Uplift into 1.7.x approved after deliberating with @brave/uplift-approvers. Please make sure that all the correct labels are being used and the associated issue is moved into the correct milestone.