Intent of overviewZoneManager.ts ×17

All 3 exact tests in this concept. Every test is marked by where it enters the hierarchy.

mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/ 3 tests
- editor/ 3 tests
  - test/ 3 tests
    
    common/ 3 tests
    
    view/ 3 tests
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/editor/test/common/view/overviewZoneManager.test|title=Editor View - OverviewZoneManager pixel ratio 1, dom height 300|occurrence=1 Introduced here
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/editor/test/common/view/overviewZoneManager.test|title=Editor View - OverviewZoneManager pixel ratio 1, dom height 600|occurrence=1 Introduced here
    
    mocha:v1|namespace=vscode@05c208e9e28d8c1c723fa08f85e2b7a96092e8e5|file=vs/editor/test/common/view/overviewZoneManager.test|title=Editor View - OverviewZoneManager pixel ratio 2, dom height 300|occurrence=1 Introduced here