Fix some bugs in how input mode is parsed.

1) Actually use the mode parsing function
2) Default to "" rather than "text" which brings the behaviour to be
more like what would be expected

Change-Id: I6a46437ac797d59810e099af1ddf564d532e05b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087497Reviewed-by: Keith Lee <keithlee@chromium.org>
Commit-Queue: John Palmer <jopalmer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748077}

chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc

@@ -234,7 +234,7 @@ class ImeObserverChromeOS : public ui::ImeObserver {
       input_context.type = input_method_private::ParseInputContextType(
           ConvertInputContextType(context));
       input_context.mode = input_method_private::ParseInputModeType(
-          ConvertInputContextType(context));
+          ConvertInputContextMode(context));
       input_context.auto_correct = ConvertInputContextAutoCorrect(context);
       input_context.auto_complete = ConvertInputContextAutoComplete(context);
       input_context.auto_capitalize =
@@ -382,7 +382,7 @@ class ImeObserverChromeOS : public ui::ImeObserver {
 
   std::string ConvertInputContextMode(
       ui::IMEEngineHandlerInterface::InputContext input_context) {
-    std::string input_mode_type = "text";
+    std::string input_mode_type = "none";  // default to nothing
     switch (input_context.mode) {
       case ui::TEXT_INPUT_MODE_SEARCH:
         input_mode_type = "search";
@@ -405,9 +405,12 @@ class ImeObserverChromeOS : public ui::ImeObserver {
       case ui::TEXT_INPUT_MODE_NONE:
         input_mode_type = "noKeyboard";
         break;
-      default:
+      case ui::TEXT_INPUT_MODE_TEXT:
         input_mode_type = "text";
         break;
+      default:
+        input_mode_type = "";
+        break;
     }
     return input_mode_type;
   }