Implement material throbber and use it in one place (Autofill card

ui/views/controls/throbber.cc

Index: ui/views/controls/throbber.cc
diff --git a/ui/views/controls/throbber.cc b/ui/views/controls/throbber.cc
index d1d5c1d892369a72213428a065f38d43ab2451a3..a520f1f580d09bdd001b0ca594aadfbff5fa4ef8 100644
--- a/ui/views/controls/throbber.cc
+++ b/ui/views/controls/throbber.cc
@@ -143,6 +143,9 @@ CheckmarkThrobber::CheckmarkThrobber()
           IDR_CHECKMARK).ToImageSkia()) {
 }
 
+CheckmarkThrobber::~CheckmarkThrobber() {
+}
+
 void CheckmarkThrobber::SetChecked(bool checked) {
   bool changed = checked != checked_;
   if (changed) {
@@ -165,4 +168,61 @@ void CheckmarkThrobber::OnPaint(gfx::Canvas* canvas) {
   }
 }
 
+// Material throbber -----------------------------------------------------------
+
+MaterialThrobber::MaterialThrobber() : preferred_diameter_(0) {
+}
+
+MaterialThrobber::~MaterialThrobber() {
+}
+
+gfx::Size MaterialThrobber::GetPreferredSize() const {
+  if (preferred_diameter_ == 0)
+    return CheckmarkThrobber::GetPreferredSize();
+
+  return gfx::Size(preferred_diameter_, preferred_diameter_);
+}
+
+int MaterialThrobber::GetHeightForWidth(int w) const {
+  return w;
+}
+
+void MaterialThrobber::OnPaint(gfx::Canvas* canvas) {
+  if (!running_) {
+    CheckmarkThrobber::OnPaint(canvas);
+    return;
+  }
+
+  gfx::Rect bounds = GetContentsBounds();
+  // Inset by half the stroke width to make sure the whole arc is inside
+  // the visible rect.
+  SkScalar stroke_width = SkIntToScalar(bounds.width()) / 10.0;
+  gfx::Rect oval = bounds;
+  int inset = SkScalarCeilToInt(stroke_width / 2.0);
+  oval.Inset(inset, inset);
+
+  // Calculate start and end points. The angles are counter-clockwise because
+  // the throbber spins counter-clockwise. The finish angle starts at 12 o'clock
+  // (90 degrees) and rotates steadily. The start angle trails 180 degrees
+  // behind, except for the first half revolution, when it stays at 12 o'clock.
+  base::TimeDelta revolution_time = base::TimeDelta::FromMilliseconds(1320);
+  base::TimeDelta elapsed_time = base::Time::Now() - start_time();
+  int64_t finish_angle = 90 + 360 * elapsed_time / revolution_time;
+  int64_t start_angle = std::max(finish_angle - 180, 90L);
+
+  SkPath path;
+  // Negate the angles to convert to the clockwise numbers Skia expects.
+  path.arcTo(gfx::RectToSkRect(oval), -start_angle,
+             -(finish_angle - start_angle), true);
+
+  SkPaint paint;
+  // TODO(estade): find a place for this color.
+  paint.setColor(SkColorSetRGB(0x42, 0x85, 0xF4));
+  paint.setStrokeCap(SkPaint::kRound_Cap);
+  paint.setStrokeWidth(stroke_width);
+  paint.setStyle(SkPaint::kStroke_Style);
+  paint.setAntiAlias(true);
+  canvas->DrawPath(path, paint);
+}
+
 }  // namespace views