DevTools: allow storing devtools preferences on the browser side.

chrome/browser/devtools/devtools_embedder_message_dispatcher.h

Index: chrome/browser/devtools/devtools_embedder_message_dispatcher.h
diff --git a/chrome/browser/devtools/devtools_embedder_message_dispatcher.h b/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
index 882bce6b949f2aa9f59ecf9642e24c26a7a246f6..badf46f83ef98cf0a0280ece1ef29ed116d0dbdd 100644
--- a/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
+++ b/chrome/browser/devtools/devtools_embedder_message_dispatcher.h
@@ -66,6 +66,11 @@ class DevToolsEmbedderMessageDispatcher {
     virtual void ZoomOut() = 0;
     virtual void ResetZoom() = 0;
     virtual void SetDevicesUpdatesEnabled(bool enabled) = 0;
+    virtual void GetPreferences(const DispatchCallback& callback) = 0;
+    virtual void SetPreference(const std::string& name,
+                               const std::string& value) = 0;
+    virtual void RemovePreference(const std::string& name) = 0;
+    virtual void ClearPreferences() = 0;
     virtual void SendMessageToBrowser(const std::string& message) = 0;
     virtual void RecordEnumeratedHistogram(const std::string& name,
                                            int sample,