[Mac] In all the plists, define the LSMinimumSystemVersion based on MACOSX_DEPLOYMENT_TARGET.

chrome/app/app-Info.plist

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
         <key>CFBundleDevelopmentRegion</key>
         <string>en</string>
         <key>CFBundleDisplayName</key>
         <string>${EXECUTABLE_NAME}</string>
         <key>CFBundleDocumentTypes</key>
         <array>
@@ skipping 218 matching lines @@
                         <array>
                                 <string>file</string>
                         </array>
                 </dict>
         </array>
         <key>LSFileQuarantineEnabled</key>
         <true/>
         <key>LSHasLocalizedDisplayName</key>
         <string>1</string>
         <key>LSMinimumSystemVersion</key>
-        <string>10.5.0</string>
+        <string>${MACOSX_DEPLOYMENT_TARGET}.0</string>
         <key>NSPrincipalClass</key>
         <string>BrowserCrApplication</string>
         <key>NSSupportsAutomaticGraphicsSwitching</key>
         <true/>
         <key>UTExportedTypeDeclarations</key>
         <array>
                 <dict>
                         <key>UTTypeConformsTo</key>
                         <array>
                                 <string>public.data</string>
                         </array>
                         <key>UTTypeDescription</key>
                         <string>Chromium Extra</string>
                         <key>UTTypeIdentifier</key>
                         <string>org.chromium.extension</string>
                         <key>UTTypeTagSpecification</key>
                         <dict>
                                 <key>public.filename-extension</key>
                                 <array>
                                         <string>crx</string>
                                 </array>
                         </dict>
                 </dict>
         </array>
 </dict>
 </plist>