Extract debugger target enumeration into a separate class

content/public/browser/devtools_http_handler.h

Index: content/public/browser/devtools_http_handler.h
diff --git a/content/public/browser/devtools_http_handler.h b/content/public/browser/devtools_http_handler.h
index d01e8011d2aba85006ca7216f3ba7a133eb11b06..3a540ddcaa64d7b834b2bd3ed8e19639cd6c3d69 100644
--- a/content/public/browser/devtools_http_handler.h
+++ b/content/public/browser/devtools_http_handler.h
@@ -19,6 +19,7 @@ class URLRequestContextGetter;
 namespace content {
 
 class DevToolsAgentHost;
+class DevToolsAgentHostBinding;
 class DevToolsHttpHandlerDelegate;
 
 // This class is used for managing DevTools remote debugging server.
@@ -26,19 +27,6 @@ class DevToolsHttpHandlerDelegate;
 // this browser.
 class DevToolsHttpHandler {
  public:
-  // Interface responsible for mapping DevToolsAgentHost instances to/from
-  // string identifiers.
-  class DevToolsAgentHostBinding {
-   public:
-    virtual ~DevToolsAgentHostBinding() {}
-
-    // Returns the mapping of DevToolsAgentHost to identifier.
-    virtual std::string GetIdentifier(DevToolsAgentHost* agent_host) = 0;
-
-    // Returns the mapping of identifier to DevToolsAgentHost.
-    virtual DevToolsAgentHost* ForIdentifier(const std::string& identifier) = 0;
-  };
-
   // Returns frontend resource id for the given resource |name|.
   CONTENT_EXPORT static int GetFrontendResourceId(
       const std::string& name);