Use GURLs instead of patterns in SetContentSetting in mic and camera

Use SetContentSettingDefaultScope() which takes GURLs directly for
CONTENT_SETTINGS_TYPE_MEDIASTREAM_MIC/CAMERA.

BUG=551747

Review URL: https://codereview.chromium.org/1754093002

Cr-Commit-Position: refs/heads/master@{#379681}
2 files changed