RFR (S): 8245087: Use ratios instead of percentages in G1HeapSizingPolicy::expansion_amount

[Thomas Schatzl]

Hi all,

   can I have reviews for this change that changes internal calculations 
to use ratios (i.e. values between 0-1) instead of percentages (0-100)?

While in this case use of percent or ratios cancels itself out I prefer 
to use ratios for calculations and if needed percent for displaying.

There is just no need to scale the ratios we have with 100, apparently 
done to make the printing code simpler, but I really prefer it the other 
way.

In the log message I also unified the code to print the "%" sign without 
whitespace before (there has been a mix of that).

Based on 8245086 also out for review.

CR:
https://bugs.openjdk.java.net/browse/JDK-8245087
Webrev:
http://cr.openjdk.java.net/~tschatzl/8245087/webrev
Testing:
hs-tier1-5

Thanks,
   Thomas