Re-Enable PlatformAppDevToolsBrowserTest.{ReOpenedWithID,ReOpenedWithURL}
Re-Enable PlatformAppDevToolsBrowserTest.{ReOpenedWithID,ReOpenedWithURL}

These were disabled ages ago when they became flaky due to corner cases
in CLs for fast-tab closure. Fast-tab closure (in that form) has been
reverted/abandoned for a while. These tests should work fine, and have
been running fine on Linux and Mac the whole time.

BUG=246634,246999

Review URL: https://codereview.chromium.org/1499053002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#364274}

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