On Windows, reduce spaces between caret and IME window. (#32567)

diff --git a/shell/platform/windows/text_input_manager_win32.cc b/shell/platform/windows/text_input_manager_win32.cc
index e3900c1..c8475d0 100644
--- a/shell/platform/windows/text_input_manager_win32.cc
+++ b/shell/platform/windows/text_input_manager_win32.cc
@@ -179,7 +179,7 @@
   COMPOSITIONFORM cf = {CFS_POINT, {x, y}};
   ::ImmSetCompositionWindow(imm_context, &cf);
 
-  CANDIDATEFORM candidate_form = {0, CFS_CANDIDATEPOS, {x, y}, {0, 0, 0, 0}};
+  CANDIDATEFORM candidate_form = {0, CFS_EXCLUDE, {x, y}, {0, 0, 0, 0}};
   ::ImmSetCandidateWindow(imm_context, &candidate_form);
 }