Use solid underline for interim selection during composition.

We introduced interim composition character highlight for Windows in
crrev.com/780377. However, we need to revert to previous UI (solid
underline) due to strong user request.

Bug: 1124602
Change-Id: Ia4ac41f9719fabb4fcdf6171f94d242472009689
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2394195Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Siye Liu <siliu@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#804834}

third_party/blink/renderer/core/editing/ime/input_method_controller.cc

@@ -51,7 +51,6 @@
 #include "third_party/blink/renderer/core/events/composition_event.h"
 #include "third_party/blink/renderer/core/frame/local_dom_window.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
-#include "third_party/blink/renderer/core/frame/visual_viewport.h"
 #include "third_party/blink/renderer/core/geometry/dom_rect.h"
 #include "third_party/blink/renderer/core/html/forms/html_input_element.h"
 #include "third_party/blink/renderer/core/html/forms/html_text_area_element.h"
@@ -724,18 +723,14 @@ void InputMethodController::AddImeTextSpans(
 
     switch (ime_text_span.GetType()) {
       case ImeTextSpan::Type::kComposition: {
-        Color background_color =
-            GetDocument().GetPage() && ime_text_span.InterimCharSelection()
-                ? LayoutTheme::GetTheme().ActiveSelectionBackgroundColor(
-                      GetDocument()
-                          .GetPage()
-                          ->GetVisualViewport()
-                          .UsedColorScheme())
-                : ime_text_span.BackgroundColor();
+        ImeTextSpanUnderlineStyle underline_style =
+            ime_text_span.InterimCharSelection()
+                ? ImeTextSpanUnderlineStyle::kSolid
+                : ime_text_span.UnderlineStyle();
         GetDocument().Markers().AddCompositionMarker(
             ephemeral_line_range, ime_text_span.UnderlineColor(),
-            ime_text_span.Thickness(), ime_text_span.UnderlineStyle(),
-            ime_text_span.TextColor(), background_color);
+            ime_text_span.Thickness(), underline_style,
+            ime_text_span.TextColor(), ime_text_span.BackgroundColor());
         break;
       }
       case ImeTextSpan::Type::kAutocorrect:

third_party/blink/renderer/core/editing/ime/input_method_controller_test.cc

@@ -1463,10 +1463,8 @@ TEST_F(InputMethodControllerTest,
 
   auto* styleable_marker =
       DynamicTo<StyleableMarker>(GetDocument().Markers().Markers()[0].Get());
-  Color background_color =
-      LayoutTheme::GetTheme().ActiveSelectionBackgroundColor(
-          GetFrame().GetPage()->GetVisualViewport().UsedColorScheme());
-  EXPECT_EQ(background_color, styleable_marker->BackgroundColor());
+  EXPECT_EQ(ImeTextSpanUnderlineStyle::kSolid,
+            styleable_marker->UnderlineStyle());
 }
 
 TEST_F(InputMethodControllerTest, CommitPlainTextWithIme_Text_SpanInsert) {