Add infrastructure enabling tests of installer upgrade scenarios....

chrome/installer/upgrade_test.gyp

+{
+  'variables': {
+    'version_py': '../../chrome/tools/build/version.py',
+    'version_path': '../../chrome/VERSION',
+    'lastchange_path': '<(SHARED_INTERMEDIATE_DIR)/build/LASTCHANGE',
+    # 'branding_dir' is set in the 'conditions' section at the bottom.

[Nico, 2014/04/03 18:17:49]

Are the variables up here used for anything?

[grt (UTC plus 2), 2014/04/03 19:16:11]

I don't remember. Possibly they were needed by one of the dependent gyp files.
If the target builds without them, then I guess they aren't needed.

[robertshield, 2014/04/03 19:35:10]

The ones above seem not to be, runhooks completes without them, I can build
without them and the code here doesn't appear to reference them. 

The ones below (msvs_use_*) appear to be referenced in common.gypi and look like
they might mutate the release build options which for this and the two
mini_installer targets are meaningful. I haven't tested to see whether they
actually do this though.

+    'msvs_use_common_release': 0,
+    'msvs_use_common_linker_extras': 0,
+  },
+  'conditions': [
+    ['OS=="win"', {
+      'target_defaults': {
+      },
+      'targets': [
+        {
+          'target_name': 'upgrade_test',
+          'msvs_guid': 'BC4D6130-FDAD-47FB-B4FD-FCAF78DCBC3C',
+          'type': 'executable',
+          'dependencies': [
+            # This dependency, although correct, results in the mini installer
+            # being rebuilt every time upgrade_test is built.  So disable it
+            # for now.
+            # TODO(grt): fix rules/targets/etc for
+            # mini_installer.gyp:mini_installer so that it does no work if
+            # nothing has changed, then un-comment this next line:
+            # 'mini_installer.gyp:mini_installer',
+            '../../base/base.gyp:test_support_base',
+            '../../testing/gtest.gyp:gtest',
+            '../chrome.gyp:common_constants',
+            '../chrome.gyp:installer_util',
+          ],
+          'include_dirs': [
+            '../..',
+          ],
+          'sources': [
+            'test/alternate_version_generator.cc',
+            'test/alternate_version_generator.h',
+            'test/pe_image_resources.cc',
+            'test/pe_image_resources.h',
+            'test/resource_loader.cc',
+            'test/resource_loader.h',
+            'test/resource_updater.cc',
+            'test/resource_updater.h',
+            'test/run_all_tests.cc',
+            'test/upgrade_test.cc',
+          ],
+        },
+      ],
+    }],
+    [ 'branding == "Chrome"', {
+      'variables': {
+         'branding_dir': '../app/theme/google_chrome',
+      },
+    }, { # else branding!="Chrome"
+      'variables': {
+         'branding_dir': '../app/theme/chromium',
+      },
+    }],
+  ],
+}
+
+# Local Variables:
+# tab-width:2
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=2 shiftwidth=2: