Add IME service flag on ChromeOS.

This flag will provide entry for users to enable the IME service.

Bug: 888885
Change-Id: Ie21e5d1afd001db6968ce69d248304fad35bc31e
Reviewed-on: https://chromium-review.googlesource.com/c/1319223Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Leo Zhang <googleo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605893}

chrome/browser/about_flags.cc

@@ -2798,6 +2798,9 @@ const FeatureEntry kFeatureEntries[] = {
      ENABLE_DISABLE_VALUE_TYPE(
          chromeos::switches::kEnableEncryptionMigration,
          chromeos::switches::kDisableEncryptionMigration)},
+    {"enable-cros-ime-service", flag_descriptions::kImeServiceName,
+     flag_descriptions::kImeServiceDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(chromeos::features::kImeServiceConnectable)},
 #endif  // OS_CHROMEOS
 #if !defined(OS_ANDROID) && defined(GOOGLE_CHROME_BUILD)
     {"enable-google-branded-context-menu",

chrome/browser/flag_descriptions.cc

@@ -3388,6 +3388,10 @@ const char kInputViewDescription[] =
     "Enable IME extensions to supply custom views for user input such as "
     "virtual keyboards.";
 
+const char kImeServiceName[] = "Enable IME service";
+const char kImeServiceDescription[] =
+    "Enable IME service to provide the IME functionality instead of NaCl";
+
 const char kLockScreenNotificationName[] = "Lock screen notification";
 const char kLockScreenNotificationDescription[] =
     "Enable notifications on the lock screen.";

chrome/browser/flag_descriptions.h

@@ -2060,6 +2060,9 @@ extern const char kGestureTypingDescription[];
 extern const char kInputViewName[];
 extern const char kInputViewDescription[];
 
+extern const char kImeServiceName[];
+extern const char kImeServiceDescription[];
+
 extern const char kLockScreenNotificationName[];
 extern const char kLockScreenNotificationDescription[];
 

tools/metrics/histograms/enums.xml

@@ -29245,6 +29245,7 @@ from previous Chrome versions.
   <int value="-1533258008" label="CalculateNativeWinOcclusion:enabled"/>
   <int value="-1532035450" label="DragTabsInTabletMode:disabled"/>
   <int value="-1532014193" label="disable-encryption-migration"/>
+  <int value="-1529907580" label="ImeServiceConnectable:disabled"/>
   <int value="-1528455406" label="OmniboxPedalSuggestions:enabled"/>
   <int value="-1520855274" label="PWAFullCodeCache:disabled"/>
   <int value="-1517518406" label="force-update-menu-type"/>
@@ -30456,6 +30457,7 @@ from previous Chrome versions.
   <int value="738868972" label="GdiTextPrinting:disabled"/>
   <int value="739938466"
       label="WebPaymentsPerMethodCanMakePaymentQuota:disabled"/>
+  <int value="740056959" label="ImeServiceConnectable:enabled"/>
   <int value="745783589" label="translate-force-trigger-on-english"/>
   <int value="745868416" label="disable-system-timezone-automatic-detection"/>
   <int value="746944193" label="enable-automatic-password-saving:disabled"/>