Control TaskScheduler initialization params in renderers via field trial.

components/task_scheduler_util/common/variations_util.h

Index: components/task_scheduler_util/common/variations_util.h
diff --git a/components/task_scheduler_util/common/variations_util.h b/components/task_scheduler_util/common/variations_util.h
index 310ed0e56f504ced9f2ff65bf7f8f7b8bbb9e99a..96de3bf2d5b6befc250de6c7bafb53aabf9bc87e 100644
--- a/components/task_scheduler_util/common/variations_util.h
+++ b/components/task_scheduler_util/common/variations_util.h
@@ -9,9 +9,14 @@
 #include <string>
 #include <vector>
 
+#include "base/strings/string_piece.h"
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/threading/platform_thread.h"
 
+namespace base {
+class CommandLine;
+}
+
 namespace task_scheduler_util {
 
 struct SchedulerImmutableWorkerPoolParams {
@@ -31,6 +36,19 @@ std::vector<base::SchedulerWorkerPoolParams> GetWorkerPoolParams(
         constant_worker_pool_params_vector,
     const std::map<std::string, std::string>& variation_params);
 
+// Adds key-value pairs from |variation_params| whose key start with

[robliao, 2017/01/03 08:00:01]

Nit: Serializes key-value pairs from |variations_params| from keys starting with
|key_prefix| ...

[fdoray, 2017/01/04 22:47:38]

Done.

+// |key_prefix| to the --task-scheduler-variation-params switch of
+// |command_line|.
+void AddVariationParamsToCommandLine(
+    const std::map<std::string, std::string> variation_params,
+    base::StringPiece key_prefix,
+    base::CommandLine* command_line);
+
+// Returns a map with key-value pairs read from the

[robliao, 2017/01/03 08:00:01]

Nit: Returns a map of key-value pairs deserialized from the...

[fdoray, 2017/01/04 22:47:38]

Done.

+// --task-scheduler-variation-params switch of |command_line|.
+std::map<std::string, std::string> GetVariationParamsFromCommandLine(
+    const base::CommandLine& command_line);
+
 }  // namespace task_scheduler_util
 
 #endif  // COMPONENTS_TASK_SCHEDULER_UTIL_COMMON_VARIATIONS_UTIL_H_