Keep per-app GUID for WebView Metrics

android_webview/browser/aw_metrics_service_client.h

Index: android_webview/browser/aw_metrics_service_client.h
diff --git a/android_webview/browser/aw_metrics_service_client.h b/android_webview/browser/aw_metrics_service_client.h
index 3b6f2e0c24abe0694cbf2894c1a66a169f661607..613f8dc83a1a92dc24a42cdf80f138f9b0de33ce 100644
--- a/android_webview/browser/aw_metrics_service_client.h
+++ b/android_webview/browser/aw_metrics_service_client.h
@@ -16,6 +16,10 @@
 
 class PrefService;
 
+namespace base {
+class FilePath;
+}
+
 namespace metrics {
 struct ClientInfo;
 class MetricsStateManager;
@@ -40,7 +44,8 @@ class AwMetricsServiceClient : public metrics::MetricsServiceClient {
   static AwMetricsServiceClient* GetInstance();
 
   void Initialize(PrefService* pref_service,
-                  net::URLRequestContextGetter* request_context);
+                  net::URLRequestContextGetter* request_context,
+                  const base::FilePath guid_file_path);
   void Finalize();
   void SetMetricsEnabled(bool enabled);
 
@@ -66,6 +71,8 @@ class AwMetricsServiceClient : public metrics::MetricsServiceClient {
   AwMetricsServiceClient();
   ~AwMetricsServiceClient() override;
 
+  void InitializeWithGUID(std::string* guid);
+
   // Callback for metrics::MetricsStateManager::Create
   bool is_reporting_enabled();