The "tree/polymer_leaves" benchmark has no benchmark tests, nor do we install
Polymer anywhere. Polymer was previously installed through `bower`, but since
we removed bower, there is no easy way to run this benchmark with Polymer.
Considering that there are no benchmark tests, nor we have an easy way to
install/vendor Polymer, we should just remove this benchmark app.
This is also based on the assumption that we want to remove the
Polymer benchmarks anyway: see: 8a05199fb9
PR Close #28568
Benchmark Directory Layout
Bazel
Under bazel the rules for laying out test files are slightly different. Use largetable/render3 as an example.
Put the perf file in current subdirectory (ie largetable) such that the same perf file can be used for each of the sub-subdirectories. (ie largetable/* should all be testable with the same perf file largetable/largetable_perf.spec.ts). Under bazel, typescript protractor spec files must end with .spec.ts or .test.ts.