90656d882 Add isDisplayingFlutterUI to FlutterViewController (flutter/engine#10816) (#38553)

git@github.com:flutter/engine.git/compare/d75af60810f6...90656d88244d

git log d75af60810f6..90656d88244d --no-merges --oneline
2019-08-14 dnfield@google.com Add isDisplayingFlutterUI to FlutterViewController (flutter/engine#10816)

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bin/internal/engine.version

-d75af60810f6d03f60d24a1a1b7257670c95ceaf
+90656d88244d0f48634a7e70b913289c7790d8ac