PerfProvider: Get collection parameters from Finch

chrome/browser/metrics/perf/random_selector.h

Index: chrome/browser/metrics/perf/random_selector.h
diff --git a/chrome/browser/metrics/perf/random_selector.h b/chrome/browser/metrics/perf/random_selector.h
index 4500525d50bd5a841560be384e55cc4fd152b18f..b8d294697694118694970422ac2cede776ac16e5 100644
--- a/chrome/browser/metrics/perf/random_selector.h
+++ b/chrome/browser/metrics/perf/random_selector.h
@@ -35,6 +35,10 @@ class RandomSelector {
       : weight(weight), value(value) {
     }
 
+    bool operator==(const WeightAndValue& other) const {
+      return weight == other.weight && value == other.value;
+    }
+
     // Probability weight for selecting this value.
     double weight;
     // Value to be returned by Select(), if selected.
@@ -44,8 +48,10 @@ class RandomSelector {
   RandomSelector();
   virtual ~RandomSelector();
 
-  // Set the probabilities for various strings.
-  void SetOdds(const std::vector<WeightAndValue>& odds);
+  // Set the probabilities for various strings. Returns false and doesn't
+  // modify the values if odds contains any invalid weights (<=0.0) or if
+  // odds is empty.
+  bool SetOdds(const std::vector<WeightAndValue>& odds);
 
   // Randomly select one of the values from the set.
   const std::string& Select();
@@ -55,7 +61,10 @@ class RandomSelector {
     return odds_.size();
   }
 
-  // Sum of the |weight| fields in the vector.
+  const std::vector<WeightAndValue>& odds() const { return odds_; }
+
+  // Sum of the |weight| fields in the vector. Returns -1.0 if odds contains any
+  // weight <= 0.0.
   static double SumWeights(const std::vector<WeightAndValue>& odds);
 
  private:
@@ -76,4 +85,7 @@ class RandomSelector {
   DISALLOW_COPY_AND_ASSIGN(RandomSelector);
 };
 
+::std::ostream& operator<<(

[Alexei Svitkine (slow), 2015/10/21 16:52:56]

Can you add a comment for why this is needed? If it's just to satisfy tests for
the macros, suggest moving this to the unittest file.

[dhsharp, 2015/10/21 18:19:04]

Added comment. It's used in two unit test files, and it needs to be global to be
used by gtest.

+    ::std::ostream& os, const RandomSelector::WeightAndValue& value);
+
 #endif  // CHROME_BROWSER_METRICS_PERF_RANDOM_SELECTOR_H_