Mojo: Fix two bugs in content handling

1. URLLoaders can't be reused, so we need to construct one
   per-load. This became too gnarly to handle with callbacks
   so I put it back to having a loader object that owns the
   URLLoader.

2. The relevant URLLoader needs to be passed to
   ContentHandler::OnConnect() so that it stays alive long
   enough to read the entire response.

BUG=

Review URL: https://codereview.chromium.org/513573002

Cr-Commit-Position: refs/heads/master@{#292460}

mojo/application_manager/application_loader.cc

@@ -23,7 +23,7 @@ ApplicationLoader::SimpleLoadCallbacks::RegisterApplication() {
 
 void ApplicationLoader::SimpleLoadCallbacks::LoadWithContentHandler(
     const GURL& content_handle_url,
-    URLResponsePtr content) {
+    URLResponsePtr url_response) {
   NOTREACHED();
 }
 

mojo/application_manager/application_loader.h

@@ -34,7 +34,7 @@ class MOJO_APPLICATION_MANAGER_EXPORT ApplicationLoader {
 
     // Load the requested application with a content handler.
     virtual void LoadWithContentHandler(const GURL& content_handler_url,
-                                        URLResponsePtr response) = 0;
+                                        URLResponsePtr url_response) = 0;
 
    protected:
     friend base::RefCounted<LoadCallbacks>;

mojo/application_manager/application_manager.cc

@@ -66,12 +66,12 @@ class ApplicationManager::LoadCallbacksImpl
   }
 
   virtual void LoadWithContentHandler(const GURL& content_handler_url,
-                                      URLResponsePtr content) OVERRIDE {
+                                      URLResponsePtr url_response) OVERRIDE {
     if (manager_) {
       manager_->LoadWithContentHandler(requested_url_,
                                        requestor_url_,
                                        content_handler_url,
-                                       content.Pass(),
+                                       url_response.Pass(),
                                        service_provider_.Pass());
     }
   }
@@ -232,7 +232,7 @@ void ApplicationManager::LoadWithContentHandler(
     const GURL& content_url,
     const GURL& requestor_url,
     const GURL& content_handler_url,
-    URLResponsePtr content,
+    URLResponsePtr url_response,
     ServiceProviderPtr service_provider) {
   ContentHandlerConnection* connection = NULL;
   URLToContentHandlerMap::iterator iter =
@@ -243,8 +243,11 @@ void ApplicationManager::LoadWithContentHandler(
     connection = new ContentHandlerConnection(this, content_handler_url);
     url_to_content_handler_[content_handler_url] = connection;
   }
+
+  InterfaceRequest<ServiceProvider> spir;
+  spir.Bind(service_provider.PassMessagePipe());
   connection->content_handler->OnConnect(
-      content_url.spec(), content.Pass(), service_provider.Pass());
+      content_url.spec(), url_response.Pass(), spir.Pass());
 }
 
 void ApplicationManager::SetLoaderForURL(scoped_ptr<ApplicationLoader> loader,

mojo/application_manager/application_manager.h

@@ -123,7 +123,7 @@ class MOJO_APPLICATION_MANAGER_EXPORT ApplicationManager {
   void LoadWithContentHandler(const GURL& content_url,
                               const GURL& requestor_url,
                               const GURL& content_handler_url,
-                              URLResponsePtr content,
+                              URLResponsePtr url_response,
                               ServiceProviderPtr service_provider);
 
   // Returns the Loader to use for a url (using default if not overridden.)

mojo/examples/content_handler_demo/content_handler_demo.cc

@@ -23,8 +23,9 @@ class ContentHandlerImpl : public InterfaceImpl<ContentHandler> {
 
  private:
   virtual void OnConnect(const mojo::String& url,
-                         URLResponsePtr content,
-                         ServiceProviderPtr service_provider) MOJO_OVERRIDE;
+                         URLResponsePtr response,
+                         InterfaceRequest<ServiceProvider> service_provider)
+      MOJO_OVERRIDE;
 
   ContentHandlerApp* content_handler_app_;
 };
@@ -71,12 +72,13 @@ class ContentHandlerApp : public ApplicationDelegate {
                                   ContentHandlerApp> content_handler_factory_;
 };
 
-void ContentHandlerImpl::OnConnect(const mojo::String& url,
-                                   URLResponsePtr content,
-                                   ServiceProviderPtr service_provider) {
+void ContentHandlerImpl::OnConnect(
+    const mojo::String& url,
+    URLResponsePtr response,
+    InterfaceRequest<ServiceProvider> service_provider) {
   printf("ContentHandler::OnConnect - url:%s - body follows\n\n",
          url.To<std::string>().c_str());
-  content_handler_app_->PrintResponse(content->body.Pass());
+  content_handler_app_->PrintResponse(response->body.Pass());
 }
 
 }  // namespace examples

mojo/services/public/interfaces/content_handler/content_handler.mojom

@@ -8,9 +8,9 @@ import "mojo/services/public/interfaces/network/url_loader.mojom"
 module mojo {
 
 interface ContentHandler {
-  OnConnect(string? url,
-            URLResponse? url_response,
-            ServiceProvider? service_provider);
+  OnConnect(string url,
+            URLResponse response,
+            ServiceProvider&? service_provider);
 };
 
 }

mojo/shell/dynamic_application_loader.h

@@ -7,6 +7,7 @@
 
 #include <map>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
@@ -44,28 +45,21 @@ class DynamicApplicationLoader : public ApplicationLoader {
                                   const GURL& url) OVERRIDE;
 
  private:
+  class Loader;
+  class LocalLoader;
+  class NetworkLoader;
+
   typedef std::map<std::string, GURL> MimeTypeToURLMap;
+  typedef base::Callback<void(Loader*)> LoaderCompleteCallback;
 
-  void LoadLocalService(const GURL& resolved_url,
-                        scoped_refptr<LoadCallbacks> callbacks);
-  void LoadNetworkService(const GURL& resolved_url,
-                          scoped_refptr<LoadCallbacks> callbacks);
-  void OnLoadNetworkServiceComplete(scoped_refptr<LoadCallbacks> callbacks,
-                                    URLResponsePtr url_response);
-  void RunLibrary(const base::FilePath& response_file,
-                  scoped_refptr<LoadCallbacks> callbacks,
-                  bool delete_file_after,
-                  bool response_path_exists);
-  void OnRunLibraryComplete(DynamicServiceRunner* runner,
-                            const base::FilePath& temp_file);
+  void LoaderComplete(Loader* loader);
 
   Context* const context_;
   scoped_ptr<DynamicServiceRunnerFactory> runner_factory_;
-  ScopedVector<DynamicServiceRunner> runners_;
   NetworkServicePtr network_service_;
-  URLLoaderPtr url_loader_;
   MimeTypeToURLMap mime_type_to_url_;
-  base::WeakPtrFactory<DynamicApplicationLoader> weak_ptr_factory_;
+  ScopedVector<Loader> loaders_;
+  LoaderCompleteCallback loader_complete_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(DynamicApplicationLoader);
 };