views: Change CardUnmaskPromptViews::FadeOutView opacity to alpha.

chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc

Index: chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc
diff --git a/chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc b/chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc
index 5d7a6c0980a4ed647dd463a3de4e474efde2f593..fce3f57021aebfad7364c7924d562200d5a24774 100644
--- a/chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc
+++ b/chrome/browser/ui/views/autofill/card_unmask_prompt_views.cc
@@ -22,6 +22,7 @@
 #include "ui/compositor/compositing_recorder.h"
 #include "ui/compositor/paint_context.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/geometry/safe_integer_conversions.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/button/checkbox.h"
 #include "ui/views/controls/combobox/combobox.h"
@@ -456,29 +457,30 @@ void CardUnmaskPromptViews::ClosePrompt() {
 }
 
 CardUnmaskPromptViews::FadeOutView::FadeOutView()
-    : fade_everything_(false), opacity_(1.0) {
+    : fade_everything_(false), alpha_(255) {
 }
 CardUnmaskPromptViews::FadeOutView::~FadeOutView() {
 }
 
 void CardUnmaskPromptViews::FadeOutView::PaintChildren(
     const ui::PaintContext& context) {
-  int alpha = static_cast<int>(255 * opacity_);
-  ui::CompositingRecorder recorder(context, alpha);
+  ui::CompositingRecorder recorder(context, alpha_);
   views::View::PaintChildren(context);
 }
 
 void CardUnmaskPromptViews::FadeOutView::OnPaint(gfx::Canvas* canvas) {
-  if (!fade_everything_ || opacity_ > 0.99)
+  if (!fade_everything_ || alpha_ == 255)
     return views::View::OnPaint(canvas);
 
-  canvas->SaveLayerAlpha(0xff * opacity_);
+  canvas->SaveLayerAlpha(alpha_);
   views::View::OnPaint(canvas);
   canvas->Restore();
 }
 
 void CardUnmaskPromptViews::FadeOutView::SetOpacity(double opacity) {
-  opacity_ = opacity;
+  DCHECK_GE(opacity, 0.0);
+  DCHECK_LE(opacity, 1.0);
+  alpha_ = gfx::ToRoundedInt(opacity * 255);

[Peter Kasting, 2015/04/07 21:45:30]

My intent was to make this function also take an int and have its callers work
in ints as well.

   SchedulePaint();
 }