Cleanup and simplify HostConfig and JsonHostConfig.

remoting/host/in_memory_host_config.cc

Index: remoting/host/in_memory_host_config.cc
diff --git a/remoting/host/in_memory_host_config.cc b/remoting/host/in_memory_host_config.cc
index 4df3ada6427cecf92550717f5785b1f87cc8c02e..3de5be7935ba407473ddb0faefc8be5270c182c3 100644
--- a/remoting/host/in_memory_host_config.cc
+++ b/remoting/host/in_memory_host_config.cc
@@ -4,6 +4,7 @@
 
 #include "remoting/host/in_memory_host_config.h"
 
+#include "base/logging.h"
 #include "base/values.h"
 
 namespace remoting {
@@ -15,28 +16,31 @@ InMemoryHostConfig::InMemoryHostConfig()
 InMemoryHostConfig::~InMemoryHostConfig() {}
 
 bool InMemoryHostConfig::GetString(const std::string& path,
-                                   std::string* out_value) {
-  base::AutoLock auto_lock(lock_);
+                                   std::string* out_value) const {
+  DCHECK(CalledOnValidThread());
   return values_->GetString(path, out_value);
 }
 
-bool InMemoryHostConfig::GetBoolean(const std::string& path, bool* out_value) {
-  base::AutoLock auto_lock(lock_);
+bool InMemoryHostConfig::GetBoolean(const std::string& path,
+                                    bool* out_value) const {
+  DCHECK(CalledOnValidThread());
   return values_->GetBoolean(path, out_value);
 }
 
-void InMemoryHostConfig::Save() {
-  // Save is NOP for in-memory host config.
+bool InMemoryHostConfig::Save() {
+  // Saving in-memory host config is not supported.
+  NOTREACHED();
+  return false;
 }
 
 void InMemoryHostConfig::SetString(const std::string& path,
                                    const std::string& in_value) {
-  base::AutoLock auto_lock(lock_);
+  DCHECK(CalledOnValidThread());
   values_->SetString(path, in_value);
 }
 
 void InMemoryHostConfig::SetBoolean(const std::string& path, bool in_value) {
-  base::AutoLock auto_lock(lock_);
+  DCHECK(CalledOnValidThread());
   values_->SetBoolean(path, in_value);
 }