Add support for single sample metrics.

components/test/components_test_suite.cc

Index: components/test/components_test_suite.cc
diff --git a/components/test/components_test_suite.cc b/components/test/components_test_suite.cc
index 6e1e3f05165fba1fa8e0c827078a9309f07f4e90..68c1190bf1f3f37393a2b8bce2c4a8fe75edc57f 100644
--- a/components/test/components_test_suite.cc
+++ b/components/test/components_test_suite.cc
@@ -17,6 +17,7 @@
 #include "base/test/test_suite.h"
 #include "build/build_config.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
+#include "mojo/edk/embedder/embedder.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
@@ -53,6 +54,8 @@ class ComponentsTestSuite : public base::TestSuite {
   void Initialize() override {
     base::TestSuite::Initialize();
 
+    mojo::edk::Init();
+
     // Initialize the histograms subsystem, so that any histograms hit in tests
     // are correctly registered with the statistics recorder and can be queried
     // by tests.