Update from https://crrev.com/312398

base/test/launcher/test_launcher.h

Index: base/test/launcher/test_launcher.h
diff --git a/base/test/launcher/test_launcher.h b/base/test/launcher/test_launcher.h
index 78a854b599796c552a22c1dec317c9618aeca80b..27909d48ee92fc637635fea4819e722928e8ecf8 100644
--- a/base/test/launcher/test_launcher.h
+++ b/base/test/launcher/test_launcher.h
@@ -11,6 +11,7 @@
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
+#include "base/test/gtest_util.h"
 #include "base/test/launcher/test_result.h"
 #include "base/test/launcher/test_results_tracker.h"
 #include "base/time/time.h"
@@ -40,6 +41,10 @@ extern const char kGTestOutputFlag[];
 // which tests and how are run.
 class TestLauncherDelegate {
  public:
+  // Called to get names of tests available for running. The delegate
+  // must put the result in |output| and return true on success.
+  virtual bool GetTests(std::vector<SplitTestName>* output) = 0;
+
   // Called before a test is considered for running. If it returns false,
   // the test is not run. If it returns true, the test will be run provided
   // it is part of the current shard.
@@ -158,6 +163,9 @@ class TestLauncher {
   std::vector<std::string> positive_test_filter_;
   std::vector<std::string> negative_test_filter_;
 
+  // Tests to use (cached result of TestLauncherDelegate::GetTests).
+  std::vector<SplitTestName> tests_;
+
   // Number of tests started in this iteration.
   size_t test_started_count_;