Change comment and explicitly default destructor

Change-Id: Idc58cb4d48207d9cbc5a674a4e86560b0e209484
Reviewed-on: https://chromium-review.googlesource.com/1131960Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Commit-Queue: Orin Jaworski <orinj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573904}

chrome/browser/ui/views/omnibox/omnibox_match_cell_view.cc

@@ -152,7 +152,7 @@ class PlaceholderImageSource : public gfx::CanvasImageSource {
   PlaceholderImageSource(const gfx::Size& canvas_size, SkColor color);
   ~PlaceholderImageSource() override;
 
-  // CanvasImageSource override:
+  // gfx::CanvasImageSource:
   void Draw(gfx::Canvas* canvas) override;
 
  private:
@@ -188,6 +188,7 @@ class EncircledImageSource : public gfx::CanvasImageSource {
   EncircledImageSource(const int radius,
                        const SkColor color,
                        const gfx::ImageSkia& image);
+  ~EncircledImageSource() override;
 
   // gfx::CanvasImageSource:
   void Draw(gfx::Canvas* canvas) override;
@@ -208,6 +209,8 @@ EncircledImageSource::EncircledImageSource(const int radius,
       color_(color),
       image_(image) {}
 
+EncircledImageSource::~EncircledImageSource() = default;
+
 void EncircledImageSource::Draw(gfx::Canvas* canvas) {
   cc::PaintFlags flags;
   flags.setAntiAlias(true);