CrOS shelf: indicator tweaks to match spec

* Reduce space to edge of screen.
* Draw the indicators as strokes, not rects, to be able to use "softer"
  flags (stroke cap, etc.).

Bug: 880578
Change-Id: Ic4268766561d2d038589f5216d22084463f551d4
Reviewed-on: https://chromium-review.googlesource.com/c/1288505Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600923}

ash/shelf/shelf_button.cc

@@ -214,25 +214,28 @@ class ShelfButton::AppStatusIndicatorView
     cc::PaintFlags flags;
     // Active and running indicators look a little different in the new UI.
     flags.setColor(active_ ? kIndicatorColorActive : kIndicatorColorRunning);
-    float indicator_width;
-    float indicator_height;
-    gfx::PointF origin;
+    flags.setAntiAlias(true);
+    flags.setStrokeCap(cc::PaintFlags::Cap::kRound_Cap);
+    flags.setStrokeJoin(cc::PaintFlags::Join::kRound_Join);
+    flags.setStrokeWidth(kStatusIndicatorThickness);
+    flags.setStyle(cc::PaintFlags::kStroke_Style);
+    float stroke_length =
+        active_ ? kStatusIndicatorActiveSize : kStatusIndicatorRunningSize;
+    gfx::PointF start;
+    gfx::PointF end;
     if (horizontal_shelf_) {
-      indicator_width =
-          active_ ? kStatusIndicatorActiveSize : kStatusIndicatorRunningSize;
-      indicator_height = kStatusIndicatorThickness;
+      start = gfx::PointF(center.x() - stroke_length / 2, center.y());
+      end = start;
+      end.Offset(stroke_length, 0);
     } else {
-      indicator_width = kStatusIndicatorThickness;
-      indicator_height =
-          active_ ? kStatusIndicatorActiveSize : kStatusIndicatorRunningSize;
+      start = gfx::PointF(center.x(), center.y() - stroke_length / 2);
+      end = start;
+      end.Offset(0, stroke_length);
     }
-    origin = gfx::PointF(center.x() - indicator_width / 2,
-                         center.y() - indicator_height / 2);
-    canvas->DrawRect(
-        gfx::ScaleRect(
-            gfx::RectF(origin, gfx::SizeF(indicator_width, indicator_height)),
-            dsf),
-        flags);
+    gfx::Path path;
+    path.moveTo(start.x() * dsf, start.y() * dsf);
+    path.lineTo(end.x() * dsf, end.y() * dsf);
+    canvas->DrawPath(path, flags);
   }
 
   // ShelfButtonAnimation::Observer

ash/shelf/shelf_constants.h

@@ -85,7 +85,7 @@ constexpr int kOverflowButtonSize = 32;
 constexpr int kOverflowButtonCornerRadiusOldUi = 2;
 
 // The distance between the edge of the shelf and the status indicators.
-constexpr int kStatusIndicatorOffsetFromShelfEdge = 2;
+constexpr int kStatusIndicatorOffsetFromShelfEdge = 1;
 
 // The direction of the focus cycling.
 enum CycleDirection { CYCLE_FORWARD, CYCLE_BACKWARD };