The first step for enabling off-the-spot IME on Pepper on ChromeOS/Linux.

chrome/browser/renderer_host/gtk_im_context_wrapper.h

Index: chrome/browser/renderer_host/gtk_im_context_wrapper.h
diff --git a/chrome/browser/renderer_host/gtk_im_context_wrapper.h b/chrome/browser/renderer_host/gtk_im_context_wrapper.h
index f41b7c199a6522975555f45fd1acb632f9621dc1..b39e830a7aa8e4189f500dd0f60d3332c4d526c1 100644
--- a/chrome/browser/renderer_host/gtk_im_context_wrapper.h
+++ b/chrome/browser/renderer_host/gtk_im_context_wrapper.h
@@ -16,6 +16,7 @@
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebTextInputType.h"
 #include "ui/base/ime/composition_text.h"
+#include "ui/gfx/rect.h"
 
 namespace gfx {
 class Rect;
@@ -52,6 +53,7 @@ class GtkIMContextWrapper {
                               const gfx::Rect& caret_rect);
   void OnFocusIn();
   void OnFocusOut();
+  void OnPpapiPluginFocusChanged(bool focused);
 
 #if !defined(TOOLKIT_VIEWS)
   // Not defined for views because the views context menu doesn't
@@ -144,6 +146,13 @@ class GtkIMContextWrapper {
   // Whether or not this widget is focused.
   bool is_focused_;
 
+  // Whether or not the focus is on a PPAPI plugin
+  bool is_ppapi_plugin_focused_;
+
+  // Saved for re-doing UpdateInputMethodState operation.
+  WebKit::WebTextInputType text_input_type_;
+  gfx::Rect caret_rect_;
+
   // Whether or not the above GtkIMContext is composing a text with an IME.
   // This flag is used in "commit" signal handler of the GtkIMContext object,
   // which determines how to submit the result text to WebKit according to this