Support device-pixel-ratio in wpt reftests.

tests/wpt/css-tests/tools/manifest/item.py

@@ -123,7 +123,7 @@ class RefTest(URLManifestItem):
     item_type = "reftest"
 
     def __init__(self, source_file, url, references, url_base="/", timeout=None,
-                 viewport_size=None, manifest=None):
+                 viewport_size=None, dpi=None, manifest=None):
         URLManifestItem.__init__(self, source_file, url, url_base=url_base, manifest=manifest)
         for _, ref_type in references:
             if ref_type not in ["==", "!="]:
@@ -131,13 +131,14 @@ class RefTest(URLManifestItem):
         self.references = tuple(references)
         self.timeout = timeout
         self.viewport_size = viewport_size
+        self.dpi = dpi
 
     @property
     def is_reference(self):
         return self.source_file.name_is_reference
 
     def meta_key(self):
-        return (self.timeout, self.viewport_size)
+        return (self.timeout, self.viewport_size, self.dpi)
 
     def to_json(self):
         rv = URLManifestItem.to_json(self)
@@ -146,6 +147,8 @@ class RefTest(URLManifestItem):
             rv["timeout"] = self.timeout
         if self.viewport_size is not None:
             rv["viewport_size"] = self.viewport_size
+        if self.dpi is not None:
+            rv["dpi"] = self.dpi
         return rv
 
     @classmethod
@@ -157,6 +160,7 @@ class RefTest(URLManifestItem):
                    url_base=manifest.url_base,
                    timeout=obj.get("timeout"),
                    viewport_size=obj.get("viewport_size"),
+                   dpi=obj.get("dpi"),
                    manifest=manifest)
 
 

tests/wpt/css-tests/tools/manifest/sourcefile.py

@@ -197,6 +197,23 @@ class SourceFile(object):
 
         return self.viewport_nodes[0].attrib.get("content", None)
 
+    @cached_property
+    def dpi_nodes(self):
+        """List of ElementTree Elements corresponding to nodes in a test that
+        specify device pixel ratios"""
+        return self.root.findall(".//{http://www.w3.org/1999/xhtml}meta[@name='device-pixel-ratio']")
+
+    @cached_property
+    def dpi(self):
+        """The device pixel ratio of a test or reference file"""
+        if not self.root:
+            return None
+
+        if not self.dpi_nodes:
+            return None
+
+        return self.dpi_nodes[0].attrib.get("content", None)
+
     @cached_property
     def testharness_nodes(self):
         """List of ElementTree Elements corresponding to nodes representing a
@@ -288,7 +305,8 @@ class SourceFile(object):
                 rv.append(TestharnessTest(self, url, timeout=self.timeout))
 
         elif self.content_is_ref_node:
-            rv = [RefTest(self, self.url, self.references, timeout=self.timeout, viewport_size=self.viewport_size)]
+            rv = [RefTest(self, self.url, self.references, timeout=self.timeout,
+                          viewport_size=self.viewport_size, dpi=self.dpi)]
 
         else:
             # If nothing else it's a helper file, which we don't have a specific type for