cmake: Initialize submodules slightly earlier

Move `git submodule init` calls to before the `AUTO_UPDATE_EXTERNALS`
block so that logic that requires initialized submodules can be added to
that block later.

CMakeLists.txt

@@ -332,6 +332,10 @@ foreach(proj ${EXTERNAL_PROJECTS})
     # Compute the path to the submodule for this external.
     file(RELATIVE_PATH ${proj}_GIT_SUBMODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR} ${${proj}_SOURCE_DIR})
 
+    # Initialize the submodule configuration now so parallel downloads do not conflict later.
+    execute_process(COMMAND ${GIT_EXECUTABLE} submodule init -- ${${proj}_GIT_SUBMODULE_PATH}
+      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+
     # Download externals as Git submodules.
     set(${proj}_DOWNLOAD_COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive -- ${${proj}_GIT_SUBMODULE_PATH})
 
@@ -341,10 +345,6 @@ foreach(proj ${EXTERNAL_PROJECTS})
       set(${proj}_UPDATE_COMMAND "")
     endif()
 
-    # Initialize the submodule configuration now so parallel downloads do not conflict later.
-    execute_process(COMMAND ${GIT_EXECUTABLE} submodule init -- ${${proj}_GIT_SUBMODULE_PATH}
-      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
-
     # now the actual project
     if(${proj}_IS_CMAKE_POD)
       if(NOT ${proj}_BINARY_DIR)
@@ -488,6 +488,10 @@ foreach(example IN ITEMS LittleDog)
   if(EXAMPLES_${example_upper})
     message(STATUS "Installation will include extra example: ${example}")
 
+    # Initialize the submodule configuration now so parallel downloads do not conflict later.
+    execute_process(COMMAND ${GIT_EXECUTABLE} submodule init -- drake/examples/${example}
+      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+
     # Download examples as Git submodules.
     set(${example}_DOWNLOAD_COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive -- drake/examples/${example})
     if(AUTO_UPDATE_EXTERNALS)
@@ -507,10 +511,6 @@ foreach(example IN ITEMS LittleDog)
     drake_forceupdate(download-${example})
     add_dependencies(drake download-${example})
     add_dependencies(download-all download-${example})
-
-    # Initialize the submodule configuration now so parallel downloads do not conflict later.
-    execute_process(COMMAND ${GIT_EXECUTABLE} submodule init -- drake/examples/${example}
-      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
   endif()
 endforeach()