Add physical_web namespace

ios/chrome/browser/application_context_impl.h

Index: ios/chrome/browser/application_context_impl.h
diff --git a/ios/chrome/browser/application_context_impl.h b/ios/chrome/browser/application_context_impl.h
index d367a09f16a659881575318b0e9607766c6a80f3..21880e9fa5928ef780e960b4707e715cd4e3293e 100644
--- a/ios/chrome/browser/application_context_impl.h
+++ b/ios/chrome/browser/application_context_impl.h
@@ -61,7 +61,7 @@ class ApplicationContextImpl : public ApplicationContext {
   component_updater::ComponentUpdateService* GetComponentUpdateService()
       override;
   CRLSetFetcher* GetCRLSetFetcher() override;
-  PhysicalWebDataSource* GetPhysicalWebDataSource() override;
+  physical_web::PhysicalWebDataSource* GetPhysicalWebDataSource() override;
 
  private:
   // Sets the locale used by the application.
@@ -85,7 +85,8 @@ class ApplicationContextImpl : public ApplicationContext {
   scoped_refptr<CRLSetFetcher> crl_set_fetcher_;
   std::unique_ptr<ios::ChromeBrowserStateManager> chrome_browser_state_manager_;
   std::string application_locale_;
-  std::unique_ptr<PhysicalWebDataSource> physical_web_data_source_;
+  std::unique_ptr<physical_web::PhysicalWebDataSource>
+      physical_web_data_source_;
 
   // Sequenced task runner for local state related I/O tasks.
   const scoped_refptr<base::SequencedTaskRunner> local_state_task_runner_;