Add logging for |old_ink_drop_state| when ink drop DCHECKs fail.

ui/views/animation/flood_fill_ink_drop_ripple.cc

Index: ui/views/animation/flood_fill_ink_drop_ripple.cc
diff --git a/ui/views/animation/flood_fill_ink_drop_ripple.cc b/ui/views/animation/flood_fill_ink_drop_ripple.cc
index 5ed22814c1b497d876ddb939af4ca9d8f588e13c..e542679e98ed3ccb0b681adeef99315ab9a2e254 100644
--- a/ui/views/animation/flood_fill_ink_drop_ripple.cc
+++ b/ui/views/animation/flood_fill_ink_drop_ripple.cc
@@ -209,7 +209,8 @@ void FloodFillInkDropRipple::AnimateStateChange(
       }
       break;
     case InkDropState::ACTION_PENDING: {
-      DCHECK(old_ink_drop_state == InkDropState::HIDDEN);
+      DCHECK_EQ(InkDropState::HIDDEN, old_ink_drop_state)
+          << " old_ink_drop_state=" << ToString(old_ink_drop_state);

[msw, 2017/01/18 23:37:08]

q: won't DCHECK_EQ already print the actual value when it doesn't match the
expected value? (ditto for other DCHECK instances you've changed to DCHECK_EQ),
these are fine if it's extra helpful to have the human-readable ToString() value
printed, but perhaps just DCHECK_EQ is enough.

[bruthig, 2017/01/18 23:53:17]

You're right it will print the int values.  e.g. "(0 vs 1)" but I'm of the
opinion that human readable is better.

 
       AnimateToOpacity(visible_opacity_,
                        GetAnimationDuration(ACTION_PENDING_FADE_IN),
@@ -228,7 +229,8 @@ void FloodFillInkDropRipple::AnimateStateChange(
     }
     case InkDropState::ACTION_TRIGGERED: {
       DCHECK(old_ink_drop_state == InkDropState::HIDDEN ||
-             old_ink_drop_state == InkDropState::ACTION_PENDING);
+             old_ink_drop_state == InkDropState::ACTION_PENDING)
+          << " old_ink_drop_state=" << ToString(old_ink_drop_state);

[msw, 2017/01/18 23:37:08]

(this one is ok, since it's not a DCHECK_EQ)

       if (old_ink_drop_state == InkDropState::HIDDEN) {
         AnimateStateChange(old_ink_drop_state, InkDropState::ACTION_PENDING,
                            animation_observer);
@@ -240,7 +242,8 @@ void FloodFillInkDropRipple::AnimateStateChange(
       break;
     }
     case InkDropState::ALTERNATE_ACTION_PENDING: {
-      DCHECK(old_ink_drop_state == InkDropState::ACTION_PENDING);
+      DCHECK_EQ(InkDropState::ACTION_PENDING, old_ink_drop_state)
+          << " old_ink_drop_state=" << ToString(old_ink_drop_state);
       AnimateToOpacity(visible_opacity_,
                        GetAnimationDuration(ALTERNATE_ACTION_PENDING),
                        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
@@ -252,7 +255,8 @@ void FloodFillInkDropRipple::AnimateStateChange(
       break;
     }
     case InkDropState::ALTERNATE_ACTION_TRIGGERED:
-      DCHECK(old_ink_drop_state == InkDropState::ALTERNATE_ACTION_PENDING);
+      DCHECK_EQ(InkDropState::ALTERNATE_ACTION_PENDING, old_ink_drop_state)
+          << " old_ink_drop_state=" << ToString(old_ink_drop_state);
       AnimateToOpacity(kHiddenOpacity, GetAnimationDuration(
                                            ALTERNATE_ACTION_TRIGGERED_FADE_OUT),
                        ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,