Fix bug in percentage increase computation for cache sensitivity analysis,

net/http/http_cache_transaction.cc

Index: net/http/http_cache_transaction.cc
===================================================================
--- net/http/http_cache_transaction.cc	(revision 159725)
+++ net/http/http_cache_transaction.cc	(working copy)
@@ -150,11 +150,9 @@
   COMPILE_ASSERT(HttpCache::Transaction::kNumValidationHeaders ==
                  arraysize(kValidationHeaders),
                  Invalid_number_of_validation_headers);
-  if (!base::StringToInt(
-          base::FieldTrialList::FindFullName("CacheSensitivityAnalysis"),
-          &sensitivity_analysis_percent_increase_)) {
-    sensitivity_analysis_percent_increase_ = 0;
-  }
+  base::StringToInt(

[rvargas (doing something else), 2012/10/03 02:01:09]

Sorry, I'm confused now. What was the bug?. Why two groups for every value?

[tburkard, 2012/10/03 16:47:21]

This change here is to make the two groups work for each value.  The reason why
we have two groups is to easily be able to spot the variance (if the
averages/percentile cutoffs for the two groups are close, low variance, if they
are far apart, high variance).  The bug was the "+ 100" below, I fixed that.

[rvargas (doing something else), 2012/10/03 22:19:05]

I thought the original behavior is what you wanted at that time... Anyway, OK,
if we have different results from both groups that's a strong signal that
something is not working :)

+      base::FieldTrialList::FindFullName("CacheSensitivityAnalysis"),
+      &sensitivity_analysis_percent_increase_);
 }
 
 HttpCache::Transaction::~Transaction() {
@@ -2285,7 +2283,7 @@
     base::TimeDelta cache_time = base::TimeTicks::Now() - cache_io_start_;
     cache_io_start_ = base::TimeTicks();
     if (sensitivity_analysis_percent_increase_ > 0) {
-      cache_time *= 100 + sensitivity_analysis_percent_increase_;
+      cache_time *= sensitivity_analysis_percent_increase_;
       cache_time /= 100;
       MessageLoop::current()->PostDelayedTask(
           FROM_HERE,