- Provide sorted instance type contribution per GC
- Visualize percentages per InstanceType based on the selected GC
- Visualize percentags per category
- Use some more arrow functions
- Introduce helper.js file

Bug: v8:7266
Change-Id: I26099cc64d9545b2de9e4574da2faf52d54ad198
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/949222
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51743}