Two omnibox color tweaks noticed while writing color mixer version.

(1) Make the "experimental keyword mode bubble outline" color match the keyword
    color.  It already did in light mode; not matching in dark mode looks like
    an oversight.
(2) Make these two colors both match the dropdown URL color.  They were already
    very close, and I believe we intended them to match, but then tweaked the
    URL color in the dropdown to guarantee sufficient contrast in the hovered
    case.

Bug: none
Change-Id: I374cd6e6a0c9f7d089114f64f6c95cc35e6b648c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1887664
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Kevin Bailey <krb@chromium.org>
Reviewed-by: Kevin Bailey <krb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710482}

chrome/browser/themes/theme_service.cc

@@ -1209,16 +1209,10 @@ base::Optional<SkColor> ThemeService::GetOmniboxColor(
         return results_bg_color();
       case TP::COLOR_OMNIBOX_RESULTS_BG_SELECTED:
         return results_bg_selected_color();
-      case TP::COLOR_OMNIBOX_SELECTED_KEYWORD:
-        if (dark)
-          return {{gfx::kGoogleGrey100, false}};
-        return url_color(results_bg_color());
       case TP::COLOR_OMNIBOX_BUBBLE_OUTLINE:
         return {{dark ? gfx::kGoogleGrey100
                       : SkColorSetA(gfx::kGoogleGrey900, 0x24),
                  false}};
-      case TP::COLOR_OMNIBOX_BUBBLE_OUTLINE_EXPERIMENTAL_KEYWORD_MODE:
-        return url_color(results_bg_color());
       case TP::COLOR_OMNIBOX_TEXT_DIMMED:
         return blend_with_clamped_contrast(bg_hovered_color());
       case TP::COLOR_OMNIBOX_RESULTS_TEXT_DIMMED:
@@ -1233,6 +1227,11 @@ base::Optional<SkColor> ThemeService::GetOmniboxColor(
                                       results_bg_selected_color());
       case TP::COLOR_OMNIBOX_RESULTS_BG_HOVERED:
         return results_bg_hovered_color();
+      case TP::COLOR_OMNIBOX_BUBBLE_OUTLINE_EXPERIMENTAL_KEYWORD_MODE:
+      case TP::COLOR_OMNIBOX_SELECTED_KEYWORD:
+        if (dark)
+          return {{gfx::kGoogleGrey100, false}};
+        FALLTHROUGH;
       case TP::COLOR_OMNIBOX_RESULTS_URL:
         return url_color(results_bg_hovered_color());
       case TP::COLOR_OMNIBOX_RESULTS_URL_SELECTED: