Use ChannelMojo between browser and service processes.

chrome/browser/service_process/service_process_control_browsertest.cc

Index: chrome/browser/service_process/service_process_control_browsertest.cc
diff --git a/chrome/browser/service_process/service_process_control_browsertest.cc b/chrome/browser/service_process/service_process_control_browsertest.cc
index a15ed69cf467120a9a73845dbbf8cf0c79ddc284..191c7a3fcca279fd5a1a010b32850d0c4a316af9 100644
--- a/chrome/browser/service_process/service_process_control_browsertest.cc
+++ b/chrome/browser/service_process/service_process_control_browsertest.cc
@@ -18,6 +18,7 @@
 #include "build/build_config.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_constants.h"
+#include "chrome/common/service_messages.h"
 #include "chrome/common/service_process_util.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "components/version_info/version_info.h"
@@ -42,7 +43,7 @@ class ServiceProcessControlBrowserTest
   MOCK_METHOD0(MockHistogramsCallback, void());
 
  protected:
-  void LaunchServiceProcessControl() {
+  void LaunchServiceProcessControl(bool wait = true) {

[Lei Zhang, 2016/09/01 06:12:01]

Can we avoid having default arguments? There can't be that many callers.

[Sam McNally, 2016/09/01 06:58:44]

Done.

     // Launch the process asynchronously.
     ServiceProcessControl::GetInstance()->Launch(
         base::Bind(&ServiceProcessControlBrowserTest::ProcessControlLaunched,
@@ -52,7 +53,8 @@ class ServiceProcessControlBrowserTest
             base::Unretained(this)));
 
     // Then run the message loop to keep things running.
-    content::RunMessageLoop();
+    if (wait)
+      content::RunMessageLoop();
   }
 
   static void QuitMessageLoop() {
@@ -171,6 +173,31 @@ IN_PROC_BROWSER_TEST_F(ServiceProcessControlBrowserTest, LaunchAndIPC) {
   EXPECT_TRUE(ServiceProcessControl::GetInstance()->Shutdown());
 }
 
+IN_PROC_BROWSER_TEST_F(ServiceProcessControlBrowserTest, LaunchAndReconnect) {
+  LaunchServiceProcessControl();
+
+  // Make sure we are connected to the service process.
+  ASSERT_TRUE(ServiceProcessControl::GetInstance()->IsConnected());
+  ServiceProcessControl::GetInstance()->Send(
+      new ServiceMsg_StayAliveForTesting);
+  ServiceProcessControl::GetInstance()->GetCloudPrintProxyInfo(
+      base::Bind(&ServiceProcessControlBrowserTest::CloudPrintInfoCallback));
+  content::RunMessageLoop();
+  Disconnect();
+
+  LaunchServiceProcessControl(false);
+
+  ASSERT_TRUE(ServiceProcessControl::GetInstance()->IsConnected());
+  content::RunMessageLoop();
+
+  ServiceProcessControl::GetInstance()->GetCloudPrintProxyInfo(
+      base::Bind(&ServiceProcessControlBrowserTest::CloudPrintInfoCallback));
+  content::RunMessageLoop();
+
+  // And then shutdown the service process.
+  EXPECT_TRUE(ServiceProcessControl::GetInstance()->Shutdown());
+}
+
 // This tests the case when a service process is launched when the browser
 // starts but we try to launch it again while setting up Cloud Print.
 // Flaky on Mac. http://crbug.com/517420