Add crash keys for the installer covering simple InstallerState fields.

chrome/installer/setup/setup_constants.h

Index: chrome/installer/setup/setup_constants.h
diff --git a/chrome/installer/setup/setup_constants.h b/chrome/installer/setup/setup_constants.h
index 4b958201cd340da8bc017cd91eccef97f2564ce3..b35c96178213c67789e51de4a229175b52d05370 100644
--- a/chrome/installer/setup/setup_constants.h
+++ b/chrome/installer/setup/setup_constants.h
@@ -28,6 +28,27 @@ extern const char kSetDisplayVersionValue[];
 
 }  // namespace switches
 
+namespace crash_keys {
+
+// Describes the version installed before starting the installer.
+extern const char kCurrentVersion[];
+
+// Describes a BrowserDistribution::Type.
+extern const char kDistributionType[];
+
+// Describes an InstallerState::Operation.
+extern const char kOperation[];
+
+// Describes an InstallerState::PackageType.
+extern const char kPackageType[];
+
+// Describes an InstallerState::Level.
+extern const char kPrivilegeLevel[];
+
+extern const char kStateKey[];
+
+}  // namespace crash_keys
+
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_SETUP_SETUP_CONSTANTS_H__