Fix system-level detection in the mini_installer.

chrome/installer/mini_installer/configuration_test.cc

Index: chrome/installer/mini_installer/configuration_test.cc
diff --git a/chrome/installer/mini_installer/configuration_test.cc b/chrome/installer/mini_installer/configuration_test.cc
index cd38950f408ecb78132d7a6afb8f5ccea432ab71..9844a9faceb9d848c6369d10d5734d41ccd59995 100644
--- a/chrome/installer/mini_installer/configuration_test.cc
+++ b/chrome/installer/mini_installer/configuration_test.cc
@@ -7,11 +7,34 @@
 #include <stddef.h>
 #include <stdlib.h>
 
+#include <memory>
+
+#include "base/environment.h"
 #include "chrome/installer/mini_installer/appid.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using mini_installer::Configuration;
 
+namespace {
+
+// A helper class to set the "GoogleUpdateIsMachine" environment variable.
+class ScopedGoogleUpdateIsMachine {
+ public:
+  explicit ScopedGoogleUpdateIsMachine(bool value)
+      : env_(base::Environment::Create()) {
+    env_->SetVar("GoogleUpdateIsMachine", value ? "1" : "0");
+  }
+
+  ~ScopedGoogleUpdateIsMachine() {
+    env_->UnSetVar("GoogleUpdateIsMachine");
+  }
+
+ private:
+  std::unique_ptr<base::Environment> env_;
+};
+
+}  // namespace
+
 class TestConfiguration : public Configuration {
  public:
   explicit TestConfiguration(const wchar_t* command_line)
@@ -160,4 +183,14 @@ TEST(MiniInstallerConfigurationTest, IsSystemLevel) {
   EXPECT_FALSE(TestConfiguration(L"spam.exe").is_system_level());
   EXPECT_FALSE(TestConfiguration(L"spam.exe --chrome").is_system_level());
   EXPECT_TRUE(TestConfiguration(L"spam.exe --system-level").is_system_level());
+
+  {
+    ScopedGoogleUpdateIsMachine env_setter(false);
+    EXPECT_FALSE(TestConfiguration(L"spam.exe").is_system_level());
+  }
+
+  {
+    ScopedGoogleUpdateIsMachine env_setter(true);
+    EXPECT_TRUE(TestConfiguration(L"spam.exe").is_system_level());
+  }
 }