Add support for icons.{src,type,density} in Manifest.

content/public/common/manifest.h

Index: content/public/common/manifest.h
diff --git a/content/public/common/manifest.h b/content/public/common/manifest.h
index 35a49b138a68b490365b8cd93e0b0eb55952d9d5..949c6100446657f66d48dc9f009351757fc65265 100644
--- a/content/public/common/manifest.h
+++ b/content/public/common/manifest.h
@@ -5,6 +5,8 @@
 #ifndef CONTENT_PUBLIC_COMMON_MANIFEST_H_
 #define CONTENT_PUBLIC_COMMON_MANIFEST_H_
 
+#include <vector>
+
 #include "base/strings/nullable_string16.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebScreenOrientationLockType.h"
@@ -24,6 +26,29 @@ struct CONTENT_EXPORT Manifest {
     DISPLAY_MODE_BROWSER
   };
 
+  // Structure representing an icon as per the Manifest specification, see:
+  // http://w3c.github.io/manifest/#dfn-icon-object
+  struct CONTENT_EXPORT Icon {
+    Icon();
+    ~Icon();
+
+    // MUST be a valid url. If an icon doesn't have a valid URL, it will not be
+    // successfully parsed, thus will not be represented in the Manifest.
+    GURL src;
+
+    // Null if the parsing failed or the field was not present. The type can be
+    // any string and doesn't have to be a valid image MIME type at this point.
+    // It is up to the consumer of the object to check if the type matches a
+    // supported type.
+    base::NullableString16 type;
+
+    // Default value is 1.0 if the value is missing or invalid.
+    double density;
+
+    // Default density. Set to 1.0.
+    static const double kDefaultDensity;
+  };
+
   Manifest();
   ~Manifest();
 
@@ -48,6 +73,10 @@ struct CONTENT_EXPORT Manifest {
   // field was not present.
   blink::WebScreenOrientationLockType orientation;
 
+  // Empty if the parsing failed, the field was not present, empty or all the
+  // icons inside the JSON array were invalid.
+  std::vector<Icon> icons;
+
   // Maximum length for all the strings inside the Manifest when it is sent over
   // IPC. The renderer process should truncate the strings before sending the
   // Manifest and the browser process must do the same when receiving it.