Hide location bar on Javascript-initiated scroll.

cc/input/top_controls_manager.cc

Index: cc/input/top_controls_manager.cc
diff --git a/cc/input/top_controls_manager.cc b/cc/input/top_controls_manager.cc
index 971ba0cbe5a1d0c56647622be75a7604295ad824..8ac642b2a0b3c732f2f2406f9eb775357e72ef1d 100644
--- a/cc/input/top_controls_manager.cc
+++ b/cc/input/top_controls_manager.cc
@@ -82,6 +82,16 @@ void TopControlsManager::UpdateTopControlsState(bool enable_hiding,
   }
 }
 
+void TopControlsManager::ShowTopControls(bool show) {
+  if (show) {
+    DCHECK(visibility_restriction_ != ALWAYS_HIDDEN);
+    SetupAnimation(SHOWING_CONTROLS);
+  } else {
+    DCHECK(visibility_restriction_ != ALWAYS_SHOWN);
+    SetupAnimation(HIDING_CONTROLS);
+  }
+}
+
 void TopControlsManager::ScrollBegin() {
   ResetAnimations();
   current_scroll_delta_ = 0.f;
@@ -153,6 +163,19 @@ void TopControlsManager::ResetAnimations() {
 }
 
 void TopControlsManager::SetupAnimation(AnimationDirection direction) {
+  DCHECK(direction != NO_ANIMATION);
+
+  if (direction == SHOWING_CONTROLS && controls_top_offset_ == 0)
+    return;
+
+  if (direction == HIDING_CONTROLS &&
+      controls_top_offset_ == -top_controls_height_) {
+    return;
+  }
+
+  if (top_controls_animation_ && animation_direction_ == direction)
+    return;
+
   top_controls_animation_ = KeyframedFloatAnimationCurve::Create();
   double start_time =
       (base::TimeTicks::Now() - base::TimeTicks()).InMillisecondsF();
@@ -166,6 +189,7 @@ void TopControlsManager::SetupAnimation(AnimationDirection direction) {
                             controls_top_offset_ + max_ending_offset,
                             EaseTimingFunction::Create()));
   animation_direction_ = direction;
+  client_->DidChangeTopControlsPosition();
 }
 
 void TopControlsManager::StartAnimationIfNecessary() {
@@ -187,11 +211,8 @@ void TopControlsManager::StartAnimationIfNecessary() {
           SHOWING_CONTROLS : HIDING_CONTROLS;
     }
 
-    if (show_controls != NO_ANIMATION &&
-        (!top_controls_animation_ || animation_direction_ != show_controls)) {
+    if (show_controls != NO_ANIMATION)
       SetupAnimation(show_controls);
-      client_->DidChangeTopControlsPosition();
-    }
   }
 }