Hold cros_component_installers in browser_process.

chrome/test/base/testing_browser_process.cc

Index: chrome/test/base/testing_browser_process.cc
diff --git a/chrome/test/base/testing_browser_process.cc b/chrome/test/base/testing_browser_process.cc
index 8896b3862abaf9b63050062fda6e9b255a834f10..2e56816d45b16d461734b79b5ccc66737dfcc51f 100644
--- a/chrome/test/base/testing_browser_process.cc
+++ b/chrome/test/base/testing_browser_process.cc
@@ -349,6 +349,25 @@ TestingBrowserProcess::pnacl_component_installer() {
   return nullptr;
 }
 
+#if defined(OS_CHROMEOS)
+component_updater::DefaultComponentInstaller*
+TestingBrowserProcess::cros_component_installer(
+    const std::string& name,
+    std::unique_ptr<component_updater::ComponentInstallerTraits>
+        installer_traits) {
+  static std::map<std::string,
+                  scoped_refptr<component_updater::DefaultComponentInstaller>>
+      cros_component_installers_;
+  auto it = cros_component_installers_.find(name);
+  if (it == cros_component_installers_.end()) {
+    cros_component_installers_[name] =
+        new component_updater::DefaultComponentInstaller(
+            std::move(installer_traits));
+  }
+  return cros_component_installers_[name].get();
+}
+#endif
+
 component_updater::SupervisedUserWhitelistInstaller*
 TestingBrowserProcess::supervised_user_whitelist_installer() {
   return nullptr;