remove reference of ash files from input_method_api.cc

ash/shell.h is referred in the file, but it turns out unnecessary.
Simply removing the include is just fine.

TBR=stevenjb@chromium.org

Bug: 646565
Test: build succeeds
Change-Id: Ic0709c0bcb4a01b5fd2744ad89fb53c0936b2088
Reviewed-on: https://chromium-review.googlesource.com/1148931
Commit-Queue: Jun Mukai <mukai@chromium.org>
Reviewed-by: Shu Chen <shuchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578902}

chrome/browser/chromeos/extensions/DEPS

@@ -4,10 +4,3 @@ include_rules = [
   "!chrome/browser/ui/views/select_file_dialog_extension.h",
   # DO NOT ADD ANY MORE ITEMS TO THE ABOVE LIST!
 ]
-
-specific_include_rules = {
-  # TODO(mash): http://crbug.com/646565.
-  "input_method_api\.cc": [
-    "+ash/shell.h",
-  ],
-}

chrome/browser/chromeos/extensions/input_method_api.cc

@@ -10,7 +10,6 @@
 #include <string>
 #include <utility>
 
-#include "ash/shell.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/values.h"