Ensure omnibox_theme.cc adapts to theme changes.

This is easily done with an override of View::OnThemeChanged()

Less easily done is a test: themes are complex. Add a test for the
selection highlight, which captures the current logic around theme
color propagation.

Bug: 801583, 819425, 704942
Change-Id: I86f3e4d9b5a30db66ad5a28d2ce7581aa9f7320b
Reviewed-on: https://chromium-review.googlesource.com/952802
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543657}

chrome/browser/ui/views/location_bar/location_bar_view.cc

@@ -649,6 +649,10 @@ void LocationBarView::Layout() {
   omnibox_view_->SetBoundsRect(location_bounds);
 }
 
+void LocationBarView::OnThemeChanged() {
+  tint_ = GetTintForProfile(profile());
+}
+
 void LocationBarView::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   RefreshLocationIcon();
   RefreshClearAllButtonIcon();

chrome/browser/ui/views/location_bar/location_bar_view.h

@@ -229,6 +229,7 @@ class LocationBarView : public LocationBar,
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
   gfx::Size CalculatePreferredSize() const override;
   void Layout() override;
+  void OnThemeChanged() override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
 
   // ChromeOmniboxEditController:
@@ -431,8 +432,8 @@ class LocationBarView : public LocationBar,
   // bar is read-only.
   const bool is_popup_mode_;
 
-  // The theme tint. Initialized based on the profile and theme settings.
-  const OmniboxTint tint_;
+  // The theme tint. Updated based on the profile and theme settings.
+  OmniboxTint tint_;
 
   // True if we should show a focus rect while the location entry field is
   // focused. Used when the toolbar is in full keyboard accessibility mode.