Always prelaunch converter/renderer on Windows 8+

Currently mozc_broker{32, 64}.exe that is registered as a start-up task
tries to pre-launch mozc_{converter, renderer}.exe when and only when
Mozc is the default IME so as not to consume unnecessary resources.

However, if Mozc is not set to the default IME, the user would have no
idea why Mozc is not available until it is used at once in non-sanboxed
application.  With this CL, we always pre-launch those processes to
avoid confusions on Windows 8 and later.

BUG=
TEST=
REF_BUG=
REF_CL=131707250
REF_TIME=2016-08-30T23:26:23+09:00
REF_TIME_RAW=1472567183 +0900

src/data/version/mozc_version_template.bzl

@@ -30,7 +30,7 @@
 
 MAJOR=2
 MINOR=18
-BUILD=2601
+BUILD=2602
 REVISION=102
 # This version represents the version of Mozc IME engine (converter, predictor,
 # etc.).  This version info is included both in the Mozc server and in the Mozc

src/win32/broker/prelauncher.cc

@@ -31,6 +31,7 @@
 
 #include "base/logging.h"
 #include "base/run_level.h"
+#include "base/system_util.h"
 #include "base/win_util.h"
 #include "client/client_interface.h"
 #include "renderer/renderer_client.h"
@@ -61,8 +62,8 @@ int RunPrelaunchProcesses(int argc, char *argv[]) {
     return kErrorLevelGeneralError;
   }
 
-  if (!ImeUtil::IsDefault()) {
-    // If Mozc is not default, do nothing.
+  if (!SystemUtil::IsWindows8OrLater() && !ImeUtil::IsDefault()) {
+    // If Mozc is not default on Windows 7 or former, do nothing.
     return kErrorLevelSuccess;
   }