Mojo Spy core first CL. Introduces mojo::Spy files

Currently only the most basic interception of message pipes.

See design document:
https://docs.google.com/a/chromium.org/document/d/11FKYXf9mSohlsgl4JmGlyWE1ScX3DKdssdjub63tkwA/edit#heading=h.fi6hmvi95gtz

BUG=360188
TEST=none

Review URL: https://codereview.chromium.org/225203002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262209 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 2 deletions

diff --git a/mojo/service_manager/service_manager.cc b/mojo/service_manager/service_manager.cc
index ab72bdf..f12249e 100644
--- a/mojo/service_manager/service_manager.cc
+++ b/mojo/service_manager/service_manager.cc
@@ -70,7 +70,9 @@ bool ServiceManager::TestAPI::HasFactoryForURL(const GURL& url) const {
       manager_->url_to_service_factory_.end();
 }
 
-ServiceManager::ServiceManager() : default_loader_(NULL) {
+ServiceManager::ServiceManager()
+    : default_loader_(NULL),
+      interceptor_(NULL) {
 }
 
 ServiceManager::~ServiceManager() {
@@ -100,7 +102,12 @@ void ServiceManager::Connect(const GURL& url,
     service_factory = new ServiceFactory(this, url);
     url_to_service_factory_[url] = service_factory;
   }
-  service_factory->ConnectToClient(client_handle.Pass());
+  if (interceptor_) {
+    service_factory->ConnectToClient(
+        interceptor_->OnConnectToClient(url, client_handle.Pass()));
+  } else {
+    service_factory->ConnectToClient(client_handle.Pass());
+  }
 }
 
 void ServiceManager::SetLoaderForURL(ServiceLoader* loader, const GURL& url) {
@@ -114,6 +121,10 @@ void ServiceManager::SetLoaderForScheme(ServiceLoader* loader,
   scheme_to_loader_[scheme] = loader;
 }
 
+void ServiceManager::SetInterceptor(Interceptor* interceptor) {
+  interceptor_ = interceptor;
+}
+
 ServiceLoader* ServiceManager::GetLoaderForURL(const GURL& url) {
   URLToLoaderMap::const_iterator url_it = url_to_loader_.find(url);
   if (url_it != url_to_loader_.end())
diff --git a/mojo/service_manager/service_manager.h b/mojo/service_manager/service_manager.h
index f2ee988..6d9ab5d 100644
--- a/mojo/service_manager/service_manager.h
+++ b/mojo/service_manager/service_manager.h
@@ -39,6 +39,15 @@ class MOJO_SERVICE_MANAGER_EXPORT ServiceManager {
     ServiceManager* manager_;
   };
 
+  // Interface class for debugging only.
+  class Interceptor {
+   public:
+    virtual ~Interceptor() {}
+    // Called when ServiceManager::Connect is called.
+    virtual ScopedMessagePipeHandle OnConnectToClient(
+        const GURL& url, ScopedMessagePipeHandle handle) = 0;
+  };
+
   ServiceManager();
   ~ServiceManager();
 
@@ -58,6 +67,8 @@ class MOJO_SERVICE_MANAGER_EXPORT ServiceManager {
   // Sets a Loader to be used for a specific url scheme.
   // Does not take ownership of |loader|.
   void SetLoaderForScheme(ServiceLoader* loader, const std::string& scheme);
+  // Allows to interpose a debugger to service connections.
+  void SetInterceptor(Interceptor* interceptor);
 
  private:
   class ServiceFactory;
@@ -77,6 +88,7 @@ class MOJO_SERVICE_MANAGER_EXPORT ServiceManager {
   URLToLoaderMap url_to_loader_;
   SchemeToLoaderMap scheme_to_loader_;
   ServiceLoader* default_loader_;
+  Interceptor* interceptor_;
 
   URLToServiceFactoryMap url_to_service_factory_;
   DISALLOW_COPY_AND_ASSIGN(ServiceManager);