[Part 1]: Update the label string.

In this CL:
1. Replace the empty label string with the label name for
different Skia components.
2. If the label string is empty, avoid sending it.
3. Append "_Skia_" at the beginning of the label string.

Bug: chromium:1164111
Change-Id: I8154f960591f0c001c6746f25e1939e0eb65d7fa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/548516
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
53 files changed