Remove hover highlight on Harmony checkboxes.

ui/views/controls/button/checkbox.cc

Index: ui/views/controls/button/checkbox.cc
diff --git a/ui/views/controls/button/checkbox.cc b/ui/views/controls/button/checkbox.cc
index fcf0ddbaffee66a28d6f240a11314cea4370dd3b..ba29b4609edf277798a9358f4efdb7f12069de51 100644
--- a/ui/views/controls/button/checkbox.cc
+++ b/ui/views/controls/button/checkbox.cc
@@ -15,6 +15,7 @@
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/resources/grit/ui_resources.h"
+#include "ui/views/animation/ink_drop_highlight.h"
 #include "ui/views/animation/ink_drop_ripple.h"
 #include "ui/views/animation/square_ink_drop_ripple.h"
 #include "ui/views/controls/button/label_button_border.h"
@@ -169,6 +170,11 @@ std::unique_ptr<InkDropRipple> Checkbox::CreateInkDropRipple() const {
   return ripple;
 }
 
+std::unique_ptr<views::InkDropHighlight> Checkbox::CreateInkDropHighlight()
+    const {
+  return nullptr;

[sky, 2017/05/26 02:28:54]

Is harmony the default everywhere not? If not, won't it effect *all* checkboxs,
not just harmony? 

[Bret, 2017/05/26 19:58:25]

Harmony isn't on by default yet. Checkboxes don't have an ink drop when harmony
is off, so this won't affect users until we launch. When Harmony is on it will
affect all views checkboxes, but we want them to look the same everywhere and
without this hover effect.

I double-checked that this is true in my testing.

+}
+
 SkColor Checkbox::GetInkDropBaseColor() const {
   return GetNativeTheme()->GetSystemColor(
       ui::NativeTheme::kColorId_ButtonEnabledColor);