Cause mini_installer tests to noop on component builds.

chrome/installer/mini_installer/mini_installer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // mini_installer.exe is the first exe that is run when chrome is being
 // installed or upgraded. It is designed to be extremely small (~5KB with no
 // extra resources linked) and it has two main jobs:
 //   1) unpack the resources (possibly decompressing some)
 //   2) run the real installer (setup.exe) with appropriate flags.
 //
@@ skipping 734 matching lines @@
     return false;
   }
 
   return true;
 }
 
 // Main function. First gets a working dir, unpacks the resources and finally
 // executes setup.exe to do the install/upgrade.
 int WMain(HMODULE module) {
 #if defined(COMPONENT_BUILD)
-  static const wchar_t kComponentBuildIncompatibleMessage[] =
-      L"mini_installer.exe is incompatible with the component build, please run"
-      L" setup.exe with the same command line instead. See"
-      L" http://crbug.com/127233#c17 for details.";
-  ::MessageBox(NULL, kComponentBuildIncompatibleMessage, NULL, MB_ICONERROR);
-  return 1;
+  if (::GetEnvironmentVariable(L"MINI_INSTALLER_TEST", NULL, 0) == 0) {
+    static const wchar_t kComponentBuildIncompatibleMessage[] =
+        L"mini_installer.exe is incompatible with the component build, please"
+        L" run setup.exe with the same command line instead. See"
+        L" http://crbug.com/127233#c17 for details.";
+    ::MessageBox(NULL, kComponentBuildIncompatibleMessage, NULL, MB_ICONERROR);
+    return 1;
+  }
 #endif
 
   // Always start with deleting potential leftovers from previous installations.
   // This can make the difference between success and failure.  We've seen
   // many installations out in the field fail due to out of disk space problems
   // so this could buy us some space.
   DeleteOldChromeTempDirectories();
 
   // TODO(grt): Make the exit codes more granular so we know where the popular
   // errors truly are.
   int exit_code = 101;
 
   // Parse the command line.
   Configuration configuration;
   if (!configuration.Initialize())
     return exit_code;
 
+  if (configuration.query_component_build()) {
+    // Return whether this is a component build then exit. This is used by

[grt (UTC plus 2), 2014/05/28 18:51:44]

nit: returning is exiting. how about
    // Exit immediately with 1 or 0 to indicate component build or not.
or something like that

[robertshield, 2014/05/28 21:27:30]

Done.

+    // the tests in /src/chrome/test/mini_installer/.
+#if defined(COMPONENT_BUILD)
+    return 1;
+#else
+    return 0;
+#endif
+  }
+
   // If the --cleanup switch was specified on the command line, then that means
   // we should only do the cleanup and then exit.
   if (ProcessNonInstallOperations(configuration, &exit_code))
     return exit_code;
 
   // First get a path where we can extract payload
   PathString base_path;
   if (!GetWorkDir(module, &base_path))
     return 101;
 
@@ skipping 65 matching lines @@
     case 1:
       dest8[count - 1] = c;
   }
 
   while (adjcount-- > 0)  // Copy the rest, 4 bytes/32 bits at a time
     *(dest32++) = fill;
 
   return dest;
 }
 }  // extern "C"