Enable 'ime' sandbox with decoder.

Start the IME service with an 'ime' sandbox when the build flag
ENABLE_CROS_IME_DECODER is true. This change is to help dev start
decoder engine easily.

By default, IME service will be started with a utility sandbox.

Bug: 837156
Change-Id: I7cefe8743298d713aeb257e48f3f7d9f9fca7564
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1743851Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Leo Zhang <googleo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#685462}

chromeos/services/ime/public/cpp/BUILD.gn

@@ -116,6 +116,7 @@ source_set("manifest") {
 
   deps = [
     "//base",
+    "//chromeos/services/ime/public/cpp:buildflags",
     "//chromeos/services/ime/public/mojom",
     "//chromeos/strings",
     "//services/service_manager/public/cpp",

chromeos/services/ime/public/cpp/manifest.cc

@@ -5,6 +5,8 @@
 #include "chromeos/services/ime/public/cpp/manifest.h"
 
 #include "base/no_destructor.h"
+#include "build/buildflag.h"
+#include "chromeos/services/ime/public/cpp/buildflags.h"
 #include "chromeos/services/ime/public/mojom/constants.mojom.h"
 #include "chromeos/services/ime/public/mojom/input_engine.mojom.h"
 #include "chromeos/strings/grit/chromeos_strings.h"
@@ -13,6 +15,16 @@
 namespace chromeos {
 namespace ime {
 
+namespace {
+
+#if BUILDFLAG(ENABLE_CROS_IME_DECODER)
+const char kImeServiceSandboxType[] = "ime";
+#else
+const char kImeServiceSandboxType[] = "utility";
+#endif
+
+}  // namespace
+
 const service_manager::Manifest& GetManifest() {
   static base::NoDestructor<service_manager::Manifest> manifest{
       service_manager::ManifestBuilder()
@@ -22,7 +34,7 @@ const service_manager::Manifest& GetManifest() {
               service_manager::ManifestOptionsBuilder()
                   .WithExecutionMode(service_manager::Manifest::ExecutionMode::
                                          kOutOfProcessBuiltin)
-                  .WithSandboxType("utility")
+                  .WithSandboxType(kImeServiceSandboxType)
                   .WithInstanceSharingPolicy(
                       service_manager::Manifest::InstanceSharingPolicy::
                           kSharedAcrossGroups)