Fix gfx::Canvas::DrawStringRectWithHalo

ui/gfx/render_text.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 "ui/gfx/render_text.h"
 
 #include <limits.h>
 
 #include <algorithm>
 #include <climits>
 
 #include "base/command_line.h"
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
 #include "third_party/icu/source/common/unicode/rbbi.h"
 #include "third_party/icu/source/common/unicode/utf16.h"
 #include "third_party/skia/include/core/SkDrawLooper.h"
 #include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
+#include "third_party/skia/include/effects/SkMorphologyImageFilter.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
 #include "ui/gfx/platform_font.h"
 #include "ui/gfx/render_text_harfbuzz.h"
 #include "ui/gfx/scoped_canvas.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/switches.h"
 #include "ui/gfx/text_elider.h"
 #include "ui/gfx/text_utils.h"
@@ skipping 231 matching lines @@
 }
 
 void SkiaTextRenderer::SetForegroundColor(SkColor foreground) {
   paint_.setColor(foreground);
 }
 
 void SkiaTextRenderer::SetShader(SkShader* shader) {
   paint_.setShader(shader);
 }
 
+void SkiaTextRenderer::SetHaloEffect() {
+  paint_.setImageFilter(SkDilateImageFilter::Create(1, 1));

[Stephen White, 2016/02/08 16:24:51]

I think there's a memory leak here.

Objects in Skia are created with a refcount of 1, and SkPaint::setImageFilter()
takes another ref (making it 2).

In Chrome and Blink, the usual pattern is something like this:

skia::RefPtr<SkImageFilter> filter =
skia::AdoptRef(SkDilateImageFilter::Create(1, 1));
paint.setImageFilter(filter.get());

[Stephen White, 2016/02/08 16:27:10]

(Or

auto filter = skia::AdoptRef(SkDilateImageFilter::Create(1, 1));

to be more modern/concise, I suppose.)

+}
+
 void SkiaTextRenderer::SetUnderlineMetrics(SkScalar thickness,
                                            SkScalar position) {
   underline_thickness_ = thickness;
   underline_position_ = position;
 }
 
 void SkiaTextRenderer::DrawPosText(const SkPoint* pos,
                                    const uint16_t* glyphs,
                                    size_t glyph_count) {
   const size_t byte_length = glyph_count * sizeof(glyphs[0]);
@@ skipping 535 matching lines @@
   }
 
   if (!text().empty() && focused())
     DrawSelection(canvas);
 
   if (cursor_enabled() && cursor_visible() && focused())
     DrawCursor(canvas, selection_model_);
 
   if (!text().empty()) {
     internal::SkiaTextRenderer renderer(canvas);
+    if (halo_effect())
+      renderer.SetHaloEffect();
     DrawVisualText(&renderer);
   }
 
   if (clip_to_display_rect())
     canvas->Restore();
 }
 
 void RenderText::DrawCursor(Canvas* canvas, const SelectionModel& position) {
   // Paint cursor. Replace cursor is drawn as rectangle for now.
   // TODO(msw): Draw a better cursor with a better indication of association.
@@ skipping 699 matching lines @@
 
   SetDisplayOffset(display_offset_.x() + delta_x);
 }
 
 void RenderText::DrawSelection(Canvas* canvas) {
   for (const Rect& s : GetSubstringBounds(selection()))
     canvas->FillRect(s, selection_background_focused_color_);
 }
 
 }  // namespace gfx