Consolidate javascript_dialog_manager.h and javascript_dialog_manager_impl.h

extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc

Index: extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc
diff --git a/extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc b/extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc
index 5522b54dbe7384c784ff961b3ca3c3bbf12fd2ef..c70386421680ce6c6434ca5e4247f2f4c71fc8fa 100644
--- a/extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc
+++ b/extensions/components/javascript_dialog_extensions_client/javascript_dialog_extension_client_impl.cc
@@ -11,6 +11,7 @@
 #include "extensions/common/extension.h"
 #include "ui/gfx/native_widget_types.h"
 
+namespace javascript_dialog_extensions_client {
 namespace {
 
 using extensions::Extension;
@@ -30,7 +31,7 @@ const Extension* GetExtensionForWebContents(
 }
 
 class JavaScriptDialogExtensionsClientImpl
-    : public JavaScriptDialogExtensionsClient {
+    : public app_modal_dialogs::JavaScriptDialogExtensionsClient {
  public:
   JavaScriptDialogExtensionsClientImpl() {}
   ~JavaScriptDialogExtensionsClientImpl() override {}
@@ -74,7 +75,10 @@ class JavaScriptDialogExtensionsClientImpl
 
 }  // namespace
 
-void InstallJavaScriptDialogExtensionsClient() {
-  SetJavaScriptDialogExtensionsClient(
-      make_scoped_ptr(new JavaScriptDialogExtensionsClientImpl));
+void InstallClient() {
+  app_modal_dialogs::JavaScriptDialogManager::GetInstance()->
+      SetExtensionsClient(
+          make_scoped_ptr(new JavaScriptDialogExtensionsClientImpl));
 }
+
+}  // namespace javascript_dialog_extensions_client