mojo: Fix double character inserts on Windows by removing a Linux hack.

ui/base/ime/input_method_auralinux.h

Index: ui/base/ime/input_method_auralinux.h
diff --git a/ui/base/ime/input_method_auralinux.h b/ui/base/ime/input_method_auralinux.h
index de5c347be21bbe1cdb1f8273b1eb0c96d00d7ee2..245055e309c39107e89626039fdedc59a8d00e62 100644
--- a/ui/base/ime/input_method_auralinux.h
+++ b/ui/base/ime/input_method_auralinux.h
@@ -14,8 +14,9 @@ namespace ui {
 // A ui::InputMethod implementation for Aura on Linux platforms. The
 // implementation details are separated to ui::LinuxInputMethodContext
 // interface.
-class InputMethodAuraLinux : public InputMethodBase,
-                             public LinuxInputMethodContextDelegate {
+class UI_BASE_EXPORT InputMethodAuraLinux
+    : public InputMethodBase,
+      public LinuxInputMethodContextDelegate {
  public:
   explicit InputMethodAuraLinux(internal::InputMethodDelegate* delegate);
   virtual ~InputMethodAuraLinux();