Use 0.2f opacity only when the shadow animation is applied.

ui/wm/core/shadow.cc

Index: ui/wm/core/shadow.cc
diff --git a/ui/wm/core/shadow.cc b/ui/wm/core/shadow.cc
index 4b621225844350015c2aa58d4dfbfb0dcd1a7414..8e42a6283757fb009fc42857819970792320807a 100644
--- a/ui/wm/core/shadow.cc
+++ b/ui/wm/core/shadow.cc
@@ -12,10 +12,9 @@
 
 namespace {
 
-// Shadow opacity for different styles.
+// The target opacity of shadow animation for different styles.
 const float kActiveShadowOpacity = 1.0f;

[James Cook, 2014/12/11 22:34:04]

I would just delete this constant and inline the use of 1.0f. I think the
existence of this variable (and its name) confused me because it implies that in
the steady-state the assets are drawn with non-1.0 opacity.

[oshima, 2014/12/12 21:23:45]

Done.

 const float kInactiveShadowOpacity = 0.2f;
-const float kSmallShadowOpacity = 1.0f;
 
 // Shadow aperture for different styles.
 // Note that this may be greater than interior inset to allow shadows with
@@ -32,18 +31,6 @@ const int kSmallInteriorInset = 4;
 // Duration for opacity animation in milliseconds.
 const int kShadowAnimationDurationMs = 100;
 
-float GetOpacityForStyle(wm::Shadow::Style style) {
-  switch (style) {
-    case wm::Shadow::STYLE_ACTIVE:
-      return kActiveShadowOpacity;
-    case wm::Shadow::STYLE_INACTIVE:
-      return kInactiveShadowOpacity;
-    case wm::Shadow::STYLE_SMALL:
-      return kSmallShadowOpacity;
-  }
-  return 1.0f;
-}
-
 int GetShadowApertureForStyle(wm::Shadow::Style style) {
   switch (style) {
     case wm::Shadow::STYLE_ACTIVE:
@@ -89,7 +76,7 @@ void Shadow::Init(Style style) {
   shadow_layer_->set_name("Shadow");
   shadow_layer_->SetVisible(true);
   shadow_layer_->SetFillsBoundsOpaquely(false);
-  shadow_layer_->SetOpacity(GetOpacityForStyle(style_));
+  shadow_layer_->SetOpacity(1.0f);

[oshima, 2014/12/12 21:23:45]

I removed this because 1.0f is default.

 }
 
 void Shadow::SetContentBounds(const gfx::Rect& content_bounds) {
@@ -111,7 +98,7 @@ void Shadow::SetStyle(Style style) {
   // animations.
   if (style == STYLE_SMALL || old_style == STYLE_SMALL) {
     UpdateImagesForStyle();
-    shadow_layer_->SetOpacity(GetOpacityForStyle(style));
+    shadow_layer_->SetOpacity(1.0f);
     return;
   }