Make default media device ID salts random by default

android_webview/browser/aw_resource_context.cc

Index: android_webview/browser/aw_resource_context.cc
diff --git a/android_webview/browser/aw_resource_context.cc b/android_webview/browser/aw_resource_context.cc
index 65682f54270345dfbb4516c055e382c89bec985f..d9205e68ed011508e1524a007106ef792127ee83 100644
--- a/android_webview/browser/aw_resource_context.cc
+++ b/android_webview/browser/aw_resource_context.cc
@@ -13,7 +13,7 @@ using content::BrowserThread;
 namespace android_webview {
 
 AwResourceContext::AwResourceContext(net::URLRequestContextGetter* getter)
-    : getter_(getter) {
+    : getter_(getter), media_device_id_salt_(CreateRandomMediaDeviceIDSalt()) {
   DCHECK(getter_);
 }
 
@@ -50,4 +50,9 @@ net::URLRequestContext* AwResourceContext::GetRequestContext() {
   return getter_->GetURLRequestContext();
 }
 
+content::ResourceContext::SaltCallback
+AwResourceContext::GetMediaDeviceIDSalt() {
+  return CreateSaltCallback(media_device_id_salt_);
+}
+
 }  // namespace android_webview