Add DCHECKs to validate ProfileIOData's list of protocols.

chrome/browser/profiles/profile_io_data.cc

Index: chrome/browser/profiles/profile_io_data.cc
diff --git a/chrome/browser/profiles/profile_io_data.cc b/chrome/browser/profiles/profile_io_data.cc
index 19646787be9606ba0fd779951ef39ee6fa95e807..8060cebf7460ee783feec9f754f82bb0b8eb5979 100644
--- a/chrome/browser/profiles/profile_io_data.cc
+++ b/chrome/browser/profiles/profile_io_data.cc
@@ -724,8 +724,9 @@ ProfileIOData* ProfileIOData::FromResourceContext(
 }
 
 // static
-bool ProfileIOData::IsHandledProtocol(const std::string& scheme) {
+bool ProfileIOData::IsBuiltInProtocol(const std::string& scheme) {
   DCHECK_EQ(scheme, base::ToLowerASCII(scheme));
+  // The list below MUST include every protocol that could return a response.
   static const char* const kProtocolList[] = {
     url::kFileScheme,
     content::kChromeDevToolsScheme,
@@ -758,13 +759,13 @@ bool ProfileIOData::IsHandledProtocol(const std::string& scheme) {
 }
 
 // static
-bool ProfileIOData::IsHandledURL(const GURL& url) {
+bool ProfileIOData::HasBuiltInProtocol(const GURL& url) {
   if (!url.is_valid()) {
     // We handle error cases.
     return true;
   }
 
-  return IsHandledProtocol(url.scheme());
+  return IsBuiltInProtocol(url.scheme());
 }
 
 // static
@@ -775,6 +776,7 @@ void ProfileIOData::InstallProtocolHandlers(
            protocol_handlers->begin();
        it != protocol_handlers->end();
        ++it) {
+    DCHECK(IsBuiltInProtocol(it->first));
     bool set_protocol = job_factory->SetProtocolHandler(
         it->first, base::WrapUnique(it->second.release()));
     DCHECK(set_protocol);
@@ -1178,44 +1180,48 @@ ProfileIOData::SetUpJobFactoryDefaults(
         protocol_handler_interceptor,
     net::NetworkDelegate* network_delegate,
     net::HostResolver* host_resolver) const {
-  // NOTE(willchan): Keep these protocol handlers in sync with
-  // ProfileIOData::IsHandledProtocol().
-  bool set_protocol = job_factory->SetProtocolHandler(
+  // NOTE(nick): It is absolutely critical for the built-in protocol handlers to
+  // be enumerated by ProfileIOData::IsBuiltInProtocol(), so use this lambda to
+  // make sure you've got it right.
+  net::URLRequestJobFactoryImpl* job_factory_ptr = job_factory.get();
+  auto install_builtin_handler = [job_factory_ptr](
+      const char* p,
+      std::unique_ptr<net::URLRequestJobFactory::ProtocolHandler> h) {
+    DCHECK(IsBuiltInProtocol(p)) << p;
+    bool set_protocol_succeeded =
+        job_factory_ptr->SetProtocolHandler(p, std::move(h));
+    DCHECK(set_protocol_succeeded);
+  };
+
+  install_builtin_handler(
       url::kFileScheme,
       base::MakeUnique<net::FileProtocolHandler>(
           content::BrowserThread::GetBlockingPool()
               ->GetTaskRunnerWithShutdownBehavior(
                   base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)));
-  DCHECK(set_protocol);
 
 #if defined(ENABLE_EXTENSIONS)
   DCHECK(extension_info_map_.get());
   // Check only for incognito (and not Chrome OS guest mode GUEST_PROFILE).
   bool is_incognito = profile_type() == Profile::INCOGNITO_PROFILE;
-  set_protocol = job_factory->SetProtocolHandler(
-      extensions::kExtensionScheme,
-      extensions::CreateExtensionProtocolHandler(is_incognito,
-                                                 extension_info_map_.get()));
-  DCHECK(set_protocol);
-  set_protocol = job_factory->SetProtocolHandler(
-      extensions::kExtensionResourceScheme,
-      CreateExtensionResourceProtocolHandler());
-  DCHECK(set_protocol);
+  install_builtin_handler(extensions::kExtensionScheme,
+                          extensions::CreateExtensionProtocolHandler(
+                              is_incognito, extension_info_map_.get()));
+  install_builtin_handler(extensions::kExtensionResourceScheme,
+                          CreateExtensionResourceProtocolHandler());
 #endif
-  set_protocol = job_factory->SetProtocolHandler(
-      url::kDataScheme, base::MakeUnique<net::DataProtocolHandler>());
-  DCHECK(set_protocol);
+  install_builtin_handler(url::kDataScheme,
+                          base::MakeUnique<net::DataProtocolHandler>());
 #if defined(OS_CHROMEOS)
   if (profile_params_) {
-    set_protocol = job_factory->SetProtocolHandler(
+    install_builtin_handler(
         content::kExternalFileScheme,
         base::MakeUnique<chromeos::ExternalFileProtocolHandler>(
             profile_params_->profile));
-    DCHECK(set_protocol);
   }
 #endif  // defined(OS_CHROMEOS)
 #if defined(OS_ANDROID)
-  set_protocol = job_factory->SetProtocolHandler(
+  install_builtin_handler(
       url::kContentScheme,
       content::ContentProtocolHandler::Create(
           content::BrowserThread::GetBlockingPool()
@@ -1223,13 +1229,13 @@ ProfileIOData::SetUpJobFactoryDefaults(
                   base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)));
 #endif
 
-  job_factory->SetProtocolHandler(
+  install_builtin_handler(
       url::kAboutScheme,
       base::MakeUnique<about_handler::AboutProtocolHandler>());
 
 #if !BUILDFLAG(DISABLE_FTP_SUPPORT)
-  job_factory->SetProtocolHandler(
-      url::kFtpScheme, net::FtpProtocolHandler::Create(host_resolver));
+  install_builtin_handler(url::kFtpScheme,
+                          net::FtpProtocolHandler::Create(host_resolver));
 #endif  // !BUILDFLAG(DISABLE_FTP_SUPPORT)
 
 #if defined(DEBUG_DEVTOOLS)