Refactor ShadowImageSource into ui/gfx/skia_util for better reuse

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.h"
 
 #include <algorithm>
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/layout_constants.h"
 #include "chrome/browser/ui/views/location_bar/location_bar_view.h"
 #include "chrome/browser/ui/views/omnibox/omnibox_result_view.h"
 #include "chrome/browser/ui/views/theme_copying_widget.h"
 #include "components/omnibox/browser/omnibox_view.h"
 #include "third_party/skia/include/core/SkDrawLooper.h"
 #include "ui/base/theme_provider.h"
 #include "ui/compositor/clip_recorder.h"
 #include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
-#include "ui/gfx/image/canvas_image_source.h"
 #include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/shadow_value.h"
-#include "ui/gfx/skia_util.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/view_targeter.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/window/non_client_view.h"
 
 namespace {
 
-// This creates a shadow image that is 1dp wide, suitable for tiling along the
-// top or bottom edge of the omnibox popup.
-class ShadowImageSource : public gfx::CanvasImageSource {
- public:
-  ShadowImageSource(const std::vector<gfx::ShadowValue>& shadows, bool bottom)
-      : gfx::CanvasImageSource(gfx::Size(1, GetHeightForShadows(shadows)),
-                               false),
-        shadows_(shadows),
-        bottom_(bottom) {}
-  ~ShadowImageSource() override {}
-
-  void Draw(gfx::Canvas* canvas) override {
-    SkPaint paint;
-    paint.setLooper(gfx::CreateShadowDrawLooperCorrectBlur(shadows_));
-    canvas->DrawRect(gfx::RectF(0, bottom_ ? -1 : size().height(), 1, 1),
-                     paint);
-  }
-
- private:
-  static int GetHeightForShadows(const std::vector<gfx::ShadowValue>& shadows) {
-    int height = 0;
-    for (const auto& shadow : shadows) {
-      height =
-          std::max(height, shadow.y() + gfx::ToCeiledInt(shadow.blur() / 2));
-    }
-    return height;
-  }
-
-  const std::vector<gfx::ShadowValue> shadows_;
-  bool bottom_;
-
-  DISALLOW_COPY_AND_ASSIGN(ShadowImageSource);
-};
-
 // Cache the shadow images so that potentially expensive shadow drawing isn't
 // repeated.
 base::LazyInstance<gfx::ImageSkia> g_top_shadow = LAZY_INSTANCE_INITIALIZER;
 base::LazyInstance<gfx::ImageSkia> g_bottom_shadow = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 class OmniboxPopupContentsView::AutocompletePopupWidget
     : public ThemeCopyingWidget,
       public base::SupportsWeakPtr<AutocompletePopupWidget> {
@@ skipping 34 matching lines @@
       size_animation_(this),
       start_margin_(0),
       end_margin_(0) {
   // The contents is owned by the LocationBarView.
   set_owned_by_client();
 
   if (g_top_shadow.Get().isNull()) {
     std::vector<gfx::ShadowValue> shadows;
     // Blur by 1dp. See comment below about blur accounting.
     shadows.emplace_back(gfx::Vector2d(), 2, SK_ColorBLACK);
-
-    auto source = new ShadowImageSource(shadows, false);
-    g_top_shadow.Get() = gfx::ImageSkia(source, source->size());
+    g_top_shadow.Get() =
+        gfx::ImageSkiaOperations::CreateHorizontalShadow(shadows, false);
   }
   if (g_bottom_shadow.Get().isNull()) {
     const int kSmallShadowBlur = 3;
     const int kLargeShadowBlur = 8;
     const int kLargeShadowYOffset = 3;
 
     std::vector<gfx::ShadowValue> shadows;
     // gfx::ShadowValue counts blur pixels both inside and outside the shape,
     // whereas these blur values only describe the outside portion, hence they
     // must be doubled.
     shadows.emplace_back(gfx::Vector2d(), 2 * kSmallShadowBlur,
                          SK_ColorBLACK);
     shadows.emplace_back(gfx::Vector2d(0, kLargeShadowYOffset),
                          2 * kLargeShadowBlur, SK_ColorBLACK);
 
-    auto source = new ShadowImageSource(shadows, true);
-    g_bottom_shadow.Get() = gfx::ImageSkia(source, source->size());
+    g_bottom_shadow.Get() =
+        gfx::ImageSkiaOperations::CreateHorizontalShadow(shadows, true);
   }
 
   SetEventTargeter(
       std::unique_ptr<views::ViewTargeter>(new views::ViewTargeter(this)));
 }
 
 void OmniboxPopupContentsView::Init() {
   // This can't be done in the constructor as at that point we aren't
   // necessarily our final class yet, and we may have subclasses
   // overriding CreateResultView.
@@ skipping 406 matching lines @@
   size_t index = GetIndexForPoint(event.location());
   if (!HasMatchAt(index))
     return;
   omnibox_view_->OpenMatch(model_->result().match_at(index), disposition,
                            GURL(), base::string16(), index);
 }
 
 OmniboxResultView* OmniboxPopupContentsView::result_view_at(size_t i) {
   return static_cast<OmniboxResultView*>(child_at(static_cast<int>(i)));
 }