manifest: rework icon selector to include small icon cut-off

chrome/browser/manifest/manifest_icon_selector_unittest.cc

Index: chrome/browser/manifest/manifest_icon_selector_unittest.cc
diff --git a/chrome/browser/manifest/manifest_icon_selector_unittest.cc b/chrome/browser/manifest/manifest_icon_selector_unittest.cc
index cff4263a61b2b4c4bee34e54d036b466339bcdb2..36bd1d44812848de8d1b7ddefcca4a83eeb4d36b 100644
--- a/chrome/browser/manifest/manifest_icon_selector_unittest.cc
+++ b/chrome/browser/manifest/manifest_icon_selector_unittest.cc
@@ -83,7 +83,7 @@ TEST_F(ManifestIconSelectorTest, MIMETypeFiltering) {
   // Icons with type specified to a MIME type that isn't a valid image MIME type
   // are ignored.
   std::vector<gfx::Size> sizes;
-  sizes.push_back(gfx::Size(10, 10));
+  sizes.push_back(gfx::Size(1024, 1024));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(
@@ -151,7 +151,7 @@ TEST_F(ManifestIconSelectorTest, PreferredSizeOfCurrentDensityIsUsedFirst) {
 TEST_F(ManifestIconSelectorTest, PreferredSizeOfDefaultDensityIsUsedSecond) {
   // This test has three icons. The first one is of density zero and is marked
   // with three sizes which are the preferred icon size for density 1, 2 and 3.
-  // The icon for density 2 and 3 have a size set to 2x2 and 3x3.
+  // The icon for density 2 and 3 have a size set to 1024x1024.
   // Regardless of the device scale factor, the icon of density 1 is going to be
   // used because it matches the preferred size.
   std::vector<gfx::Size> sizes_1;
@@ -163,10 +163,10 @@ TEST_F(ManifestIconSelectorTest, PreferredSizeOfDefaultDensityIsUsedSecond) {
                               GetPreferredIconSizeInDp() * 3));
 
   std::vector<gfx::Size> sizes_2;
-  sizes_2.push_back(gfx::Size(2, 2));
+  sizes_2.push_back(gfx::Size(1024, 1024));
 
   std::vector<gfx::Size> sizes_3;
-  sizes_3.push_back(gfx::Size(3, 3));
+  sizes_3.push_back(gfx::Size(1024, 1024));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(CreateIcon("http://foo.com/icon_x1.png", "", 1.0, sizes_1));
@@ -192,7 +192,7 @@ TEST_F(ManifestIconSelectorTest, DeviceDensityFirst) {
   // This test has three icons each are marked with sizes set to the preferred
   // icon size for the associated density.
   std::vector<gfx::Size> sizes;
-  sizes.push_back(gfx::Size(2, 2));
+  sizes.push_back(gfx::Size(1024, 1024));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(CreateIcon("http://foo.com/icon_x1.png", "", 1.0, sizes));
@@ -216,7 +216,7 @@ TEST_F(ManifestIconSelectorTest, DeviceDensityFallback) {
   // If there is no perfect icon but and no icon of the current display density,
   // an icon of density 1.0 will be used.
   std::vector<gfx::Size> sizes;
-  sizes.push_back(gfx::Size(2, 2));
+  sizes.push_back(gfx::Size(1024, 1024));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(CreateIcon("http://foo.com/icon_x1.png", "", 1.0, sizes));
@@ -227,11 +227,47 @@ TEST_F(ManifestIconSelectorTest, DeviceDensityFallback) {
   EXPECT_EQ("http://foo.com/icon_x1.png", url.spec());
 }
 
+TEST_F(ManifestIconSelectorTest, DeviceDensityMatchRejectsTooSmall) {
+  // If we have to resort to density matching to find icons, then an icon of
+  // the correct size has not been found. Make sure that an icon which is just
+  // slightly smaller than one density bucket below the device is not chosen
+  // even if the density matches.
+  std::vector<gfx::Size> sizes_1_2;
+  std::vector<gfx::Size> sizes_3;
+
+  sizes_1_2.push_back(gfx::Size(47, 47));
+  sizes_3.push_back(gfx::Size(95, 95));
+
+  std::vector<content::Manifest::Icon> icons;
+  icons.push_back(CreateIcon("http://foo.com/icon_x1.png", "", 1.0, sizes_1_2));
+  icons.push_back(CreateIcon("http://foo.com/icon_x2.png", "", 2.0, sizes_1_2));
+  icons.push_back(CreateIcon("http://foo.com/icon_x3.png", "", 3.0, sizes_3));
+
+  // Nothing matches here because there is a density scale factor lower bound of
+  // of 1.0 which since there is no density bucket smaller than the one
+  // associated with this scale factor.
+  SetDisplayDeviceScaleFactor(1.0f);
+  GURL url = FindBestMatchingIcon(icons);
+  EXPECT_TRUE(url.is_empty());
+
+  // Nothing matches here as the icon is just smaller than the icon size
+  // one density bucket below (i.e. 96 is expected and 48 is the minimum).
+  SetDisplayDeviceScaleFactor(2.0f);
+  url = FindBestMatchingIcon(icons);
+  EXPECT_TRUE(url.is_empty());
+
+  // Nothing matches here as the icon is just smaller than the icon size
+  // one density bucket below (i.e. 144 is expected and 96 is the minimum).
+  SetDisplayDeviceScaleFactor(3.0f);
+  url = FindBestMatchingIcon(icons);
+  EXPECT_TRUE(url.is_empty());
+}
+
 TEST_F(ManifestIconSelectorTest, DoNotUseOtherDensities) {
   // If there are only icons of densities that are not the current display
   // density or the default density, they are ignored.
   std::vector<gfx::Size> sizes;
-  sizes.push_back(gfx::Size(2, 2));
+  sizes.push_back(gfx::Size(1024, 1024));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(CreateIcon("http://foo.com/icon_x2.png", "", 2.0, sizes));
@@ -243,7 +279,7 @@ TEST_F(ManifestIconSelectorTest, DoNotUseOtherDensities) {
 
 TEST_F(ManifestIconSelectorTest, NotSquareIconsAreIgnored) {
   std::vector<gfx::Size> sizes;
-  sizes.push_back(gfx::Size(20, 2));
+  sizes.push_back(gfx::Size(1024, 1023));
 
   std::vector<content::Manifest::Icon> icons;
   icons.push_back(CreateIcon("http://foo.com/icon.png", "", 1.0, sizes));
@@ -264,7 +300,7 @@ TEST_F(ManifestIconSelectorTest, ClosestIconToPreferred) {
   int big = GetPreferredIconSizeInDp() * 2;
   int very_big = GetPreferredIconSizeInDp() * 4;
 
-  // (very_small, bit_small) => bit_small
+  // (very_small, bit_small) => empty (since both are too small)
   {
     std::vector<gfx::Size> sizes_1;
     sizes_1.push_back(gfx::Size(very_small, very_small));
@@ -277,10 +313,10 @@ TEST_F(ManifestIconSelectorTest, ClosestIconToPreferred) {
     icons.push_back(CreateIcon("http://foo.com/icon.png", "", 1.0, sizes_2));
 
     GURL url = FindBestMatchingIcon(icons);
-    EXPECT_EQ("http://foo.com/icon.png", url.spec());
+    EXPECT_EQ("", url.spec());
   }
 
-  // (very_small, bit_small, smaller) => bit_small
+  // (very_small, bit_small, smaller) => empty (since both are too small)
   {
     std::vector<gfx::Size> sizes_1;
     sizes_1.push_back(gfx::Size(very_small, very_small));
@@ -297,7 +333,7 @@ TEST_F(ManifestIconSelectorTest, ClosestIconToPreferred) {
     icons.push_back(CreateIcon("http://foo.com/icon_no.png", "", 1.0, sizes_3));
 
     GURL url = FindBestMatchingIcon(icons);
-    EXPECT_EQ("http://foo.com/icon.png", url.spec());
+    EXPECT_EQ("", url.spec());
   }
 
   // (very_big, big) => big