Add ability to constrain dominant color selection to a HSL range.

ui/gfx/color_analysis_unittest.cc

Index: ui/gfx/color_analysis_unittest.cc
diff --git a/ui/gfx/color_analysis_unittest.cc b/ui/gfx/color_analysis_unittest.cc
index 9592d0d38cd496aed15936997d1cdf122ce491bf..043246d249b3688a642460f54c329afe19cf6d26 100644
--- a/ui/gfx/color_analysis_unittest.cc
+++ b/ui/gfx/color_analysis_unittest.cc
@@ -10,6 +10,8 @@
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/color_utils.h"
+#include "ui/gfx/image/image.h"
 #include "ui/gfx/rect.h"
 
 using color_utils::FindClosestColor;
@@ -87,6 +89,22 @@ const unsigned char k1x3BlueRed[] = {
   0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82
 };
 
+const color_utils::HSL kDefaultLowerBound = {-1, -1, 0.15};
+const color_utils::HSL kDefaultUpperBound = {-1, -1, 0.85};
+
+// Creates a 1-dimensional png of the pixel colors found in |colors|.
+scoped_refptr<base::RefCountedMemory> CreateTestPNG(
+    const std::vector<SkColor>& colors) {
+  SkBitmap bitmap;
+  bitmap.setConfig(SkBitmap::kARGB_8888_Config, colors.size(), 1);
+  bitmap.allocPixels();
+  SkAutoLockPixels lock(bitmap);
+  for (size_t i = 0; i < colors.size(); ++i) {
+    bitmap.eraseArea(SkIRect::MakeXYWH(i, 0, 1, 1), colors[i]);
+  }
+  return gfx::Image::CreateFrom1xBitmap(bitmap).As1xPNGBytes();
+}
+
 class MockKMeanImageSampler : public color_utils::KMeanImageSampler {
  public:
   MockKMeanImageSampler() : current_result_index_(0) {
@@ -162,13 +180,13 @@ TEST_F(ColorAnalysisTest, CalculatePNGKMeanAllWhite) {
               k1x1White,
               k1x1White + sizeof(k1x1White) / sizeof(unsigned char))));
 
-  SkColor color =
-      color_utils::CalculateKMeanColorOfPNG(png, 100, 600, &test_sampler);
+  SkColor color = color_utils::CalculateKMeanColorOfPNG(
+      png, kDefaultLowerBound, kDefaultUpperBound, &test_sampler);
 
   EXPECT_EQ(color, SK_ColorWHITE);
 }
 
-TEST_F(ColorAnalysisTest, CalculatePNGKMeanIgnoreWhite) {
+TEST_F(ColorAnalysisTest, CalculatePNGKMeanIgnoreWhiteLightness) {
   MockKMeanImageSampler test_sampler;
   test_sampler.AddSample(0);
   test_sampler.AddSample(1);
@@ -180,10 +198,10 @@ TEST_F(ColorAnalysisTest, CalculatePNGKMeanIgnoreWhite) {
              k1x3BlueWhite,
              k1x3BlueWhite + sizeof(k1x3BlueWhite) / sizeof(unsigned char))));
 
-  SkColor color =
-      color_utils::CalculateKMeanColorOfPNG(png, 100, 600, &test_sampler);
+  SkColor color = color_utils::CalculateKMeanColorOfPNG(
+      png, kDefaultLowerBound, kDefaultUpperBound, &test_sampler);
 
-  EXPECT_EQ(color, SkColorSetARGB(0xFF, 0x00, 0x00, 0xFF));
+  EXPECT_EQ(SkColorSetARGB(0xFF, 0x00, 0x00, 0xFF), color);
 }
 
 TEST_F(ColorAnalysisTest, CalculatePNGKMeanPickMostCommon) {
@@ -198,10 +216,49 @@ TEST_F(ColorAnalysisTest, CalculatePNGKMeanPickMostCommon) {
              k1x3BlueRed,
              k1x3BlueRed + sizeof(k1x3BlueRed) / sizeof(unsigned char))));
 
+  SkColor color = color_utils::CalculateKMeanColorOfPNG(
+      png, kDefaultLowerBound, kDefaultUpperBound, &test_sampler);
+
+  EXPECT_EQ(SkColorSetARGB(0xFF, 0xFF, 0x00, 0x00), color);
+}
+
+TEST_F(ColorAnalysisTest, CalculatePNGKMeanIgnoreRedHue) {
+  MockKMeanImageSampler test_sampler;
+  test_sampler.AddSample(0);
+  test_sampler.AddSample(1);
+  test_sampler.AddSample(2);
+
+  std::vector<SkColor> colors(4, SK_ColorRED);
+  colors[1] = SK_ColorBLUE;
+
+  scoped_refptr<base::RefCountedMemory> png = CreateTestPNG(colors);
+
+  SkColor color =
+      color_utils::CalculateKMeanColorOfPNG(png,
+                                            color_utils::HSL{0.2, -1, 0.15},
+                                            color_utils::HSL{0.8, -1, 0.85},
+                                            &test_sampler);
+
+  EXPECT_EQ(SK_ColorBLUE, color);
+}
+
+TEST_F(ColorAnalysisTest, CalculatePNGKMeanIgnoreGreySaturation) {
+  MockKMeanImageSampler test_sampler;
+  test_sampler.AddSample(0);
+  test_sampler.AddSample(1);
+  test_sampler.AddSample(2);
+
+  std::vector<SkColor> colors(4, SK_ColorGRAY);
+  colors[1] = SK_ColorBLUE;
+
+  scoped_refptr<base::RefCountedMemory> png = CreateTestPNG(colors);
   SkColor color =
-      color_utils::CalculateKMeanColorOfPNG(png, 100, 600, &test_sampler);
+      color_utils::CalculateKMeanColorOfPNG(png,
+                                            color_utils::HSL{-1, 0.3, -1},
+                                            color_utils::HSL{-1, 1, -1},
+                                            &test_sampler);
 
-  EXPECT_EQ(color, SkColorSetARGB(0xFF, 0xFF, 0x00, 0x00));
+  EXPECT_EQ(SK_ColorBLUE, color);
 }
 
 TEST_F(ColorAnalysisTest, GridSampler) {