Remove support for the web manifest icon density member.

content/public/common/manifest.cc

Index: content/public/common/manifest.cc
diff --git a/content/public/common/manifest.cc b/content/public/common/manifest.cc
index e38a9043c377bf01026996775396a5ed4a70dead..86a6d41d4c3a44a441772eac8a0e7ce6360f13f8 100644
--- a/content/public/common/manifest.cc
+++ b/content/public/common/manifest.cc
@@ -6,7 +6,6 @@
 
 namespace content {
 
-const double Manifest::Icon::kDefaultDensity = 1;
 // We need to provide a value here which is out of the range of a 32-bit integer
 // since otherwise we would not be able to check whether a theme color was valid
 // or not. The simplest way to do this is to simply add one to the maximum
@@ -15,9 +14,7 @@ const int64_t Manifest::kInvalidOrMissingColor =
     static_cast<int64_t>(std::numeric_limits<int32_t>::max()) + 1;
 const size_t Manifest::kMaxIPCStringLength = 4 * 1024;
 
-Manifest::Icon::Icon()
-    : density(kDefaultDensity) {
-}
+Manifest::Icon::Icon() { }
 
 Manifest::Icon::Icon(const Icon& other) = default;