Mark side-effect-free methods/attributes with simple return types

Adds [Affects=Nothing] to common IDL methods/attributes with return
types: short, long, double, int, boolean, DOMString, USVString.

Followups will whitelist ones that use DOMWrapper and update style
or layout.
List of some common attributes: https://goo.gl/qGd2i7

Bug: 829571
Change-Id: I4c335b7eeac449bd7454df7f829f393469d84387
Reviewed-on: https://chromium-review.googlesource.com/1013126Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Erik Luo <luoe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551456}

third_party/WebKit/LayoutTests/http/tests/inspector-protocol/side-effects/evaluate-embedder-side-effect-free-attributes-expected.txt

 Tests that evaluating V8-embedder callbacks allows side-effect-free attribute getters. Should not crash.
-Checking: `div.isConnected` for no side effect
 

third_party/WebKit/LayoutTests/http/tests/inspector-protocol/side-effects/evaluate-embedder-side-effect-free-attributes.js

@@ -4,9 +4,45 @@
 
   await session.evaluate(`
     var div = document.createElement('div');
+    div.id = 'foo';
+    div.className = 'bar baz';
+    var textNode = document.createTextNode('footext');
+    div.appendChild(textNode);
   `);
 
-  await checkHasNoSideEffect('div.isConnected');
+  // Sanity check: test that setters are not allowed on whitelisted accessors.
+  await checkHasSideEffect(`document.title = "foo"`);
+
+  // Document
+  await checkHasNoSideEffect(`document.domain`);
+  await checkHasNoSideEffect(`document.referrer`);
+  await checkHasNoSideEffect(`document.cookie`);
+  await checkHasNoSideEffect(`document.title`);
+
+  // Element
+  await checkHasNoSideEffect(`div.tagName`);
+  await checkHasNoSideEffect(`div.id`);
+  await checkHasNoSideEffect(`div.className`);
+
+  // Node
+  var testNodes = ['div', 'document', 'textNode'];
+  for (var node of testNodes) {
+    await checkHasNoSideEffect(`${node}.nodeType`);
+    await checkHasNoSideEffect(`${node}.nodeName`);
+    await checkHasNoSideEffect(`${node}.nodeValue`);
+    await checkHasNoSideEffect(`${node}.textContent`);
+    await checkHasNoSideEffect(`${node}.isConnected`);
+  }
+
+  // ParentNode
+  await checkHasNoSideEffect(`document.childElementCount`);
+  await checkHasNoSideEffect(`div.childElementCount`);
+
+  // Window
+  await checkHasNoSideEffect(`devicePixelRatio`);
+  await checkHasNoSideEffect(`screenX`);
+  await checkHasNoSideEffect(`screenY`);
+
   testRunner.completeTest();
 
 
@@ -19,7 +55,6 @@
   }
 
   async function checkExpression(expression, expectSideEffect) {
-    testRunner.log(`Checking: \`${expression}\` for ${expectSideEffect ? '' : 'no'} side effect`);
     var response = await dp.Runtime.evaluate({expression, throwOnSideEffect: true});
     var hasSideEffect = false;
     var exceptionDetails = response.result.exceptionDetails;
@@ -27,7 +62,7 @@
         exceptionDetails.exception.description.startsWith('EvalError: Possible side-effect in debug-evaluate'))
       hasSideEffect = true;
     if (hasSideEffect !== expectSideEffect) {
-      testRunner.log(`FAIL: hasSideEffect = ${hasSideEffect}, expectSideEffect = ${expectSideEffect}`);
+      testRunner.log(`FAIL: "${expression}" hasSideEffect = ${hasSideEffect}, expectSideEffect = ${expectSideEffect}`);
       testRunner.completeTest();
       return;
     }

third_party/WebKit/LayoutTests/http/tests/inspector-protocol/side-effects/evaluate-embedder-side-effect-free-methods-expected.txt

 Tests that evaluating V8-embedder callbacks allows side-effect-free methods. Should not crash.
-Checking: `global_performance.now()` for no side effect
 

third_party/WebKit/LayoutTests/http/tests/inspector-protocol/side-effects/evaluate-embedder-side-effect-free-methods.js

@@ -4,9 +4,34 @@
 
   await session.evaluate(`
     var global_performance = window.performance;
+    var div = document.createElement('div');
+    div.setAttribute('attr1', 'attr1-value');
+    div.setAttribute('attr2', 'attr2-value');
+    var textNode = document.createTextNode('footext');
+    var divNoAttrs = document.createElement('div');
   `);
 
-  await checkHasNoSideEffect('global_performance.now()');
+  // Element
+  await checkHasNoSideEffect(`div.getAttributeNames()`);
+  await checkHasNoSideEffect(`divNoAttrs.getAttributeNames()`);
+  await checkHasNoSideEffect(`div.getAttribute()`);
+  await checkHasNoSideEffect(`div.getAttribute('attr1')`);
+  await checkHasNoSideEffect(`div.getAttribute({})`);
+  await checkHasNoSideEffect(`divNoAttrs.getAttribute('attr1')`);
+  await checkHasNoSideEffect(`div.hasAttribute()`);
+  await checkHasNoSideEffect(`div.hasAttribute('attr1')`);
+  await checkHasNoSideEffect(`div.hasAttribute({})`);
+  await checkHasNoSideEffect(`divNoAttrs.hasAttribute('attr1')`);
+
+  // Node
+  await checkHasNoSideEffect(`div.contains(textNode)`);
+  await checkHasNoSideEffect(`div.contains()`);
+  await checkHasNoSideEffect(`div.contains({})`);
+  await checkHasNoSideEffect(`textNode.contains(textNode)`);
+
+  // Window
+  await checkHasNoSideEffect(`global_performance.now()`);
+
   testRunner.completeTest();
 
 
@@ -19,7 +44,6 @@
   }
 
   async function checkExpression(expression, expectSideEffect) {
-    testRunner.log(`Checking: \`${expression}\` for ${expectSideEffect ? '' : 'no'} side effect`);
     var response = await dp.Runtime.evaluate({expression, throwOnSideEffect: true});
     var hasSideEffect = false;
     var exceptionDetails = response.result.exceptionDetails;
@@ -27,7 +51,7 @@
         exceptionDetails.exception.description.startsWith('EvalError: Possible side-effect in debug-evaluate'))
       hasSideEffect = true;
     if (hasSideEffect !== expectSideEffect) {
-      testRunner.log(`FAIL: hasSideEffect = ${hasSideEffect}, expectSideEffect = ${expectSideEffect}`);
+      testRunner.log(`FAIL: ${expression} hasSideEffect = ${hasSideEffect}, expectSideEffect = ${expectSideEffect}`);
       testRunner.completeTest();
       return;
     }

third_party/blink/renderer/core/dom/document.idl

@@ -93,9 +93,9 @@ typedef (HTMLScriptElement or SVGScriptElement) HTMLOrSVGScriptElement;
     // resource metadata management
 
     [PutForwards=href, Unforgeable] readonly attribute Location? location;
-    [RaisesException=Setter] attribute USVString domain;
-    readonly attribute USVString referrer;
-    [RaisesException, RuntimeCallStatsCounter=DocumentCookie] attribute DOMString cookie;
+    [Affects=Nothing, RaisesException=Setter] attribute USVString domain;
+    [Affects=Nothing] readonly attribute USVString referrer;
+    [Affects=Nothing, RaisesException, RuntimeCallStatsCounter=DocumentCookie] attribute DOMString cookie;
     readonly attribute DOMString lastModified;
     readonly attribute DocumentReadyState readyState;
 
@@ -103,7 +103,7 @@ typedef (HTMLScriptElement or SVGScriptElement) HTMLOrSVGScriptElement;
     // Named getter is implemented without IDL code generation for better
     // performance. See LocalWindowProxy.cpp.
     // getter object (DOMString name);
-    [CEReactions, CustomElementCallbacks] attribute DOMString title;
+    [Affects=Nothing, CEReactions, CustomElementCallbacks] attribute DOMString title;
     [CEReactions, CustomElementCallbacks] attribute DOMString dir;
     [CEReactions, RaisesException=Setter, CustomElementCallbacks, PerWorldBindings] attribute HTMLElement? body;
     readonly attribute HTMLHeadElement? head;

third_party/blink/renderer/core/dom/element.idl

@@ -30,10 +30,10 @@ interface Element : Node {
     readonly attribute DOMString? namespaceURI;
     readonly attribute DOMString? prefix;
     readonly attribute DOMString localName;
-    readonly attribute DOMString tagName;
+    [Affects=Nothing] readonly attribute DOMString tagName;
 
-    [CEReactions, Reflect] attribute DOMString id;
-    [CEReactions, Reflect=class] attribute DOMString className;
+    [Affects=Nothing, CEReactions, Reflect] attribute DOMString id;
+    [Affects=Nothing, CEReactions, Reflect=class] attribute DOMString className;
     [SameObject, PerWorldBindings, PutForwards=value] readonly attribute DOMTokenList classList;
     [Unscopable, CEReactions, Reflect] attribute DOMString slot;
 
@@ -45,14 +45,14 @@ interface Element : Node {
 
     boolean hasAttributes();
     [SameObject, PerWorldBindings, ImplementedAs=attributesForBindings] readonly attribute NamedNodeMap attributes;
-    sequence<DOMString> getAttributeNames();
-    DOMString? getAttribute(DOMString name);
+    [Affects=Nothing] sequence<DOMString> getAttributeNames();
+    [Affects=Nothing] DOMString? getAttribute(DOMString name);
     DOMString? getAttributeNS(DOMString? namespaceURI, DOMString localName);
     [RaisesException, CEReactions, CustomElementCallbacks] void setAttribute(DOMString name, DOMString value);
     [RaisesException, CEReactions, CustomElementCallbacks] void setAttributeNS(DOMString? namespaceURI, DOMString name, DOMString value);
     [CEReactions, CustomElementCallbacks] void removeAttribute(DOMString name);
     [CEReactions, CustomElementCallbacks] void removeAttributeNS(DOMString? namespaceURI, DOMString localName);
-    boolean hasAttribute(DOMString name);
+    [Affects=Nothing] boolean hasAttribute(DOMString name);
     boolean hasAttributeNS(DOMString? namespaceURI, DOMString localName);
 
     Attr? getAttributeNode(DOMString name);

third_party/blink/renderer/core/dom/node.idl

@@ -33,8 +33,8 @@ interface Node : EventTarget {
     const unsigned short DOCUMENT_TYPE_NODE = 10;
     const unsigned short DOCUMENT_FRAGMENT_NODE = 11;
     const unsigned short NOTATION_NODE = 12; // historical
-    [ImplementedAs=getNodeType] readonly attribute unsigned short nodeType;
-    [RuntimeCallStatsCounter=NodeName] readonly attribute DOMString nodeName;
+    [Affects=Nothing, ImplementedAs=getNodeType] readonly attribute unsigned short nodeType;
+    [Affects=Nothing, RuntimeCallStatsCounter=NodeName] readonly attribute DOMString nodeName;
 
     readonly attribute USVString baseURI;
 
@@ -50,9 +50,9 @@ interface Node : EventTarget {
     [PerWorldBindings] readonly attribute Node? nextSibling;
     [MeasureAs=NodeGetRootNode] Node getRootNode(optional GetRootNodeOptions options);
 
-    [CEReactions, CustomElementCallbacks] attribute DOMString? nodeValue;
+    [Affects=Nothing, CEReactions, CustomElementCallbacks] attribute DOMString? nodeValue;
 
-    [CEReactions, CustomElementCallbacks] attribute DOMString? textContent;
+    [Affects=Nothing, CEReactions, CustomElementCallbacks] attribute DOMString? textContent;
     [CEReactions, CustomElementCallbacks] void normalize();
 
     [NewObject, DoNotTestNewObject, CEReactions, CustomElementCallbacks, RaisesException] Node cloneNode(optional boolean deep = false);
@@ -66,7 +66,7 @@ interface Node : EventTarget {
     const unsigned short DOCUMENT_POSITION_CONTAINED_BY = 0x10;
     const unsigned short DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC = 0x20;
     unsigned short compareDocumentPosition(Node other);
-    boolean contains(Node? other);
+    [Affects=Nothing] boolean contains(Node? other);
 
     DOMString? lookupPrefix(DOMString? namespaceURI);
     DOMString? lookupNamespaceURI(DOMString? prefix);

third_party/blink/renderer/core/dom/parent_node.idl

@@ -37,7 +37,7 @@
     [SameObject, PerWorldBindings] readonly attribute HTMLCollection children;
     [PerWorldBindings] readonly attribute Element? firstElementChild;
     [PerWorldBindings] readonly attribute Element? lastElementChild;
-    readonly attribute unsigned long childElementCount;
+    [Affects=Nothing] readonly attribute unsigned long childElementCount;
 
     [Unscopable, RaisesException, CEReactions, CustomElementCallbacks] void prepend((Node or DOMString)... nodes);
     [Unscopable, RaisesException, CEReactions, CustomElementCallbacks] void append((Node or DOMString)... nodes);

third_party/blink/renderer/core/frame/window.idl

@@ -149,11 +149,11 @@
     [RuntimeEnabled=VisualViewportAPI, Replaceable, SameObject] readonly attribute VisualViewport visualViewport;
 
     // client
-    [Replaceable] readonly attribute long screenX;
-    [Replaceable] readonly attribute long screenY;
+    [Affects=Nothing, Replaceable] readonly attribute long screenX;
+    [Affects=Nothing, Replaceable] readonly attribute long screenY;
     [Replaceable] readonly attribute long outerWidth;
     [Replaceable] readonly attribute long outerHeight;
-    [Replaceable] readonly attribute double devicePixelRatio;
+    [Affects=Nothing, Replaceable] readonly attribute double devicePixelRatio;
 
     // Selection API
     // https://w3c.github.io/selection-api/#extensions-to-window-interface