Fix several issues in TSF support on Windows.

This CL fixes two issues with the TSF support on windows.
1. Add TS_SS_TRANSITORY flag to the return value of TsfTextStore::GetStatus.
  By adding the flag, Korean reconversion feature is disabled. User can only
  do conversion during composition. Editing frameworks may not support Korean
  reconversion by design.

2. Fix Japanese IME implicit commit on draft.js framework.
  Editing frameworks like draft.js may manage their own selection during
  composition. We should not set selection after inserting composition text
  during composition.

Bug: 657623
Change-Id: Ic9fb3d9187b2a1228807b15132e20e3227bf1de8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504035
Commit-Queue: Siye Liu <siliu@microsoft.com>
Reviewed-by: Yohei Yukawa <yukawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638356}

ui/base/ime/win/tsf_text_store.cc

@@ -219,7 +219,8 @@ STDMETHODIMP TSFTextStore::GetStatus(TS_STATUS* status) {
 
   status->dwDynamicFlags = 0;
   // We don't support hidden text.
-  status->dwStaticFlags = TS_SS_NOHIDDENTEXT;
+  // TODO(IME): Remove TS_SS_TRANSITORY to support Korean reconversion
+  status->dwStaticFlags = TS_SS_TRANSITORY | TS_SS_NOHIDDENTEXT;
 
   return S_OK;
 }
@@ -1201,7 +1202,6 @@ void TSFTextStore::CommitTextAndEndCompositionIfAny(size_t old_size,
     const base::string16& new_committed_string = string_buffer_document_.substr(
         new_committed_string_offset, new_committed_string_size);
     text_input_client_->InsertText(new_committed_string);
-    text_input_client_->SetEditableSelectionRange(selection_);
   }
 }
 

ui/base/ime/win/tsf_text_store_unittest.cc

@@ -387,7 +387,8 @@ TEST_F(TSFTextStoreTest, GetStatusTest) {
   TS_STATUS status = {};
   EXPECT_EQ(S_OK, text_store_->GetStatus(&status));
   EXPECT_EQ(0u, status.dwDynamicFlags);
-  EXPECT_EQ((ULONG)(TS_SS_NOHIDDENTEXT), status.dwStaticFlags);
+  EXPECT_EQ((ULONG)(TS_SS_TRANSITORY | TS_SS_NOHIDDENTEXT),
+            status.dwStaticFlags);
 }
 
 TEST_F(TSFTextStoreTest, QueryInsertTest) {