ui: Add out-of-line copy ctors for complex classes.

ui/base/ime/chromeos/component_extension_ime_manager.h

Index: ui/base/ime/chromeos/component_extension_ime_manager.h
diff --git a/ui/base/ime/chromeos/component_extension_ime_manager.h b/ui/base/ime/chromeos/component_extension_ime_manager.h
index 33fe88ee52ff4454256735a65c2c3a9f05194de2..d5d90d8489cdff6f7a02f7de29436f9e580fac5f 100644
--- a/ui/base/ime/chromeos/component_extension_ime_manager.h
+++ b/ui/base/ime/chromeos/component_extension_ime_manager.h
@@ -22,6 +22,7 @@ namespace chromeos {
 // Represents an engine in component extension IME.
 struct UI_BASE_IME_EXPORT ComponentExtensionEngine {
   ComponentExtensionEngine();
+  ComponentExtensionEngine(const ComponentExtensionEngine& other);
   ~ComponentExtensionEngine();
   std::string engine_id;  // The engine id.
   std::string display_name;  // The display name.
@@ -36,6 +37,7 @@ struct UI_BASE_IME_EXPORT ComponentExtensionEngine {
 // Represents a component extension IME.
 struct UI_BASE_IME_EXPORT ComponentExtensionIME {
   ComponentExtensionIME();
+  ComponentExtensionIME(const ComponentExtensionIME& other);
   ~ComponentExtensionIME();
   std::string id;  // extension id.
   std::string manifest;  // the contents of manifest.json