Bug 1118978 part 3. Add support for DependsOn=DeviceState. r=peterv

dom/bindings/Codegen.py

@@ -8177,7 +8177,12 @@ class CGMemberJITInfo(CGThing):
         dependsOn = self.member.dependsOn
         assert affects in IDLInterfaceMember.AffectsValues
         assert dependsOn in IDLInterfaceMember.DependsOnValues
-        return affects == "Nothing" and dependsOn != "Everything"
+        # Things that are DependsOn=DeviceState are not movable, because we
+        # don't want them coalesced with each other or loop-hoisted, since
+        # their return value can change even if nothing is going on from our
+        # point of view.
+        return (affects == "Nothing" and
+                (dependsOn != "Everything" and dependsOn != "DeviceState"))
 
     def aliasSet(self):
         """Returns the alias set to store in the jitinfo.  This may not be the
@@ -8189,7 +8194,7 @@ class CGMemberJITInfo(CGThing):
         dependsOn = self.member.dependsOn
         assert dependsOn in IDLInterfaceMember.DependsOnValues
 
-        if dependsOn == "Nothing":
+        if dependsOn == "Nothing" or dependsOn == "DeviceState":
             assert self.member.affects == "Nothing"
             return "AliasNone"
 

dom/bindings/parser/WebIDL.py

@@ -3044,7 +3044,7 @@ class IDLInterfaceMember(IDLObjectWithIdentifier):
     )
 
     AffectsValues = ("Nothing", "Everything")
-    DependsOnValues = ("Nothing", "DOMState", "Everything")
+    DependsOnValues = ("Nothing", "DOMState", "DeviceState", "Everything")
 
     def __init__(self, location, identifier, tag):
         IDLObjectWithIdentifier.__init__(self, location, None, identifier)
@@ -3425,9 +3425,10 @@ class IDLAttribute(IDLInterfaceMember):
             if not attr.hasValue():
                 raise WebIDLError("[DependsOn] takes an identifier",
                                   [attr.location])
-            if attr.value() == "Nothing" and not self.readonly:
-                raise WebIDLError("[DependsOn=Nothing] only allowed on "
-                                  "readonly attributes",
+            if (attr.value() != "Everything" and attr.value() != "DOMState" and
+                not self.readonly):
+                raise WebIDLError("[DependsOn=%s] only allowed on "
+                                  "readonly attributes" % attr.value(),
                                   [attr.location, self.location])
             self._setDependsOn(attr.value())
         elif (identifier == "Pref" or

dom/bindings/test/TestBindingHeader.h

@@ -187,9 +187,11 @@ public:
   int8_t DomDependentByte();
   int8_t SetDomDependentByte(int8_t);
   int8_t ConstantByte();
+  int8_t DeviceStateDependentByte();
   int8_t ReturnByteSideEffectFree();
   int8_t ReturnDOMDependentByte();
   int8_t ReturnConstantByte();
+  int8_t ReturnDeviceStateDependentByte();
 
   void UnsafePrerenderMethod();
   int32_t UnsafePrerenderWritable();

dom/bindings/test/TestCodeGen.webidl

@@ -163,12 +163,16 @@ interface TestInterface {
   attribute byte domDependentByte;
   [Affects=Nothing, DependsOn=Nothing]
   readonly attribute byte constantByte;
+  [DependsOn=DeviceState, Affects=Nothing]
+  readonly attribute byte deviceStateDependentByte;
   [Affects=Nothing]
   byte returnByteSideEffectFree();
   [Affects=Nothing, DependsOn=DOMState]
   byte returnDOMDependentByte();
   [Affects=Nothing, DependsOn=Nothing]
   byte returnConstantByte();
+  [DependsOn=DeviceState, Affects=Nothing]
+  byte returnDeviceStateDependentByte();
 
   [UnsafeInPrerendering]
   void unsafePrerenderMethod();

dom/bindings/test/TestExampleGen.webidl

@@ -42,12 +42,16 @@ interface TestExampleInterface {
   attribute byte domDependentByte;
   [Affects=Nothing, DependsOn=Nothing]
   readonly attribute byte constantByte;
+  [DependsOn=DeviceState, Affects=Nothing]
+  readonly attribute byte deviceStateDependentByte;
   [Affects=Nothing]
   byte returnByteSideEffectFree();
   [Affects=Nothing, DependsOn=DOMState]
   byte returnDOMDependentByte();
   [Affects=Nothing, DependsOn=Nothing]
   byte returnConstantByte();
+  [DependsOn=DeviceState, Affects=Nothing]
+  byte returnDeviceStateDependentByte();
 
   readonly attribute short readonlyShort;
   attribute short writableShort;

dom/bindings/test/TestJSImplGen.webidl

@@ -51,12 +51,16 @@ interface TestJSImplInterface {
   attribute byte domDependentByte;
   [Affects=Nothing, DependsOn=Nothing]
   readonly attribute byte constantByte;
+  [DependsOn=DeviceState, Affects=Nothing]
+  readonly attribute byte deviceStateDependentByte;
   [Affects=Nothing]
   byte returnByteSideEffectFree();
   [Affects=Nothing, DependsOn=DOMState]
   byte returnDOMDependentByte();
   [Affects=Nothing, DependsOn=Nothing]
   byte returnConstantByte();
+  [DependsOn=DeviceState, Affects=Nothing]
+  byte returnDeviceStateDependentByte();
 
   readonly attribute short readonlyShort;
   attribute short writableShort;