Perform ClientHello padding if the field trial is enabled

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 9ef53eeac4556f6865d2b244199b8d94a453161e..0bb75b00a3bc48b0d4e9d92103b573ab919b502b 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -75,6 +75,7 @@
 #include "net/spdy/spdy_session.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/default_channel_id_store.h"
+#include "net/ssl/ssl_socket_config_service.h"
 #include "net/url_request/data_protocol_handler.h"
 #include "net/url_request/file_protocol_handler.h"
 #include "net/url_request/ftp_protocol_handler.h"
@@ -140,6 +141,10 @@ const char kSpdyFieldTrialSpdy4ControlGroupName[] = "Spdy4Control";
 // Field trial for Cache-Control: stale-while-revalidate directive.
 const char kStaleWhileRevalidateFieldTrialName[] = "StaleWhileRevalidate";
 
+// Field trial for ClientHello padding.
+const char kClientHelloFieldTrialName[] = "FastRadioPadding";
+const char kClientHelloFieldTrialEnabledGroupName[] = "Enabled";
+
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 void ObserveKeychainEvents() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -733,6 +738,8 @@ void IOThread::InitAsync() {
   globals_->proxy_script_fetcher_context.reset(
       ConstructProxyScriptFetcherContext(globals_, net_log_));
 
+  ConfigureSSLSocketConfigService(command_line);
+
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   // Start observing Keychain events. This needs to be done on the UI thread,
   // as Keychain services requires a CFRunLoop.
@@ -1006,6 +1013,7 @@ void IOThread::InitializeNetworkSessionParamsFromGlobals(
   params->use_stale_while_revalidate = globals.use_stale_while_revalidate;
   params->testing_fixed_http_port = globals.testing_fixed_http_port;
   params->testing_fixed_https_port = globals.testing_fixed_https_port;
+  params->ssl_socket_config_service = globals.ssl_socket_config_service.get();
   globals.enable_tcp_fast_open_for_ssl.CopyToIfSet(
       &params->enable_tcp_fast_open_for_ssl);
 
@@ -1142,6 +1150,15 @@ void IOThread::ConfigureQuic(const base::CommandLine& command_line) {
   ConfigureQuicGlobals(command_line, group, params, globals_);
 }
 
+void IOThread::ConfigureSSLSocketConfigService(
+    const base::CommandLine& command_line) {
+  // Always fetch the field trial group to ensure it is reported correctly.
+  std::string group =
+      base::FieldTrialList::FindFullName(kClientHelloFieldTrialName);
+
+  ConfigureSSLSocketConfigServiceGlobals(command_line, group, globals_);
+}
+
 // static
 void IOThread::ConfigureQuicGlobals(
     const base::CommandLine& command_line,
@@ -1298,6 +1315,21 @@ double IOThread::GetAlternateProtocolProbabilityThreshold(
 }
 
 // static
+void IOThread::ConfigureSSLSocketConfigServiceGlobals(
+    const base::CommandLine& command_line,
+    base::StringPiece client_hello_trial_group,
+    Globals* globals) {
+  globals->ssl_socket_config_service.reset(new net::SSLSocketConfigService());
+
+  if (client_hello_trial_group.starts_with(
+          kClientHelloFieldTrialEnabledGroupName)) {
+    globals->ssl_socket_config_service->EnableFastRadioPadding();
+  } else {
+    globals->ssl_socket_config_service->DisableFastRadioPadding();
+  }
+}
+
+// static
 bool IOThread::ShouldQuicAlwaysRequireHandshakeConfirmation(
     const VariationParameters& quic_trial_params) {
   return LowerCaseEqualsASCII(