Add V8 bindings support for instrumenting methods for the identifiability study.

Bug: 973801
Change-Id: Ie2de8e36520d28ea0063ab6c54695786eb1de5c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2353028
Commit-Queue: Dylan Cutler <dylancutler@google.com>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799848}

third_party/blink/renderer/bindings/IDLExtendedAttributes.md

@@ -990,7 +990,7 @@ This attribute must be accompanied by either `[Measure]` or `[MeasureAs]`.
 [HighEntropy, Measure] const INTERESTING_CONSTANT = 1;
 ```
 
-Attributes labeled with `[HighEntropy=Direct]` are simple surfaces which can be expressed as a sequence of bytes without any need for additional parsing logic.
+Attributes and methods labeled with `[HighEntropy=Direct]` are simple surfaces which can be expressed as a sequence of bytes without any need for additional parsing logic.
 For now, this label is only supported for attribute getters, although the `[HighEntropy]` label is supported more broadly.
 
 ```webidl

third_party/blink/renderer/bindings/scripts/v8_methods.py

@@ -126,7 +126,8 @@ def use_local_result(method):
             or 'NewObject' in extended_attributes
             or 'RaisesException' in extended_attributes
             or idl_type.is_union_type or idl_type.is_dictionary
-            or idl_type.is_explicit_nullable)
+            or idl_type.is_explicit_nullable
+            or v8_utilities.high_entropy(method) == 'Direct')
 
 
 def runtime_call_stats_context(interface, method):

third_party/blink/renderer/bindings/templates/methods.cc.tmpl

@@ -244,7 +244,7 @@ if (!{{argument.local_cpp_variable}}.IsUndefinedOrNull() && !{{argument.local_cp
 {######################################}
 {% macro cpp_method_call(method, v8_set_return_value, cpp_value) %}
 {# Local variables #}
-{% if method.is_call_with_execution_context %}
+{% if method.is_call_with_execution_context or method.high_entropy == 'Direct' %}
 {# [ConstructorCallWith=ExecutionContext] or [CallWith=ExecutionContext] #}
 {% if method.is_constructor %}
 ExecutionContext* execution_context = ToExecutionContext(
@@ -270,6 +270,9 @@ Document& document = *ToLocalDOMWindow(
 {{method.cpp_type}} impl = {{cpp_value}};
 {% elif method.use_local_result %}
 {{method.cpp_type}} result = {{cpp_value}};
+{% if method.high_entropy == 'Direct' %}
+Dactyloscoper::RecordDirectSurface(execution_context, WebFeature::k{{method.measure_as('Method')}}, result);
+{% endif %}
 {% endif %}
 {# Post-call #}
 {% if method.is_raises_exception %}

third_party/blink/renderer/bindings/tests/idls/core/test_object.idl

@@ -472,11 +472,14 @@ interface TestObject {
     [HighEntropy,MeasureAs=TestAttributeHighEntropy] attribute DOMString highEntropyAttributeWithMeasureAs;
     [HighEntropy,MeasureAs=TestAttributeHighEntropy] readonly attribute DOMString highEntropyReadonlyAttributeWithMeasureAs;
 
-    // [HighEntropy=Direct]
+    // [HighEntropy=Direct] attributes
     [HighEntropy=Direct,MeasureAs=TestAttributeHighEntropyUnsignedLong] readonly attribute unsigned long highEntropyDirectUnsignedLong;
     [HighEntropy=Direct,MeasureAs=TestAttributeHighEntropyDOMString] readonly attribute DOMString highEntropyDirectDomString;
     [HighEntropy=Direct,MeasureAs=TestAttributeHighEntropyArrayDOMString] readonly attribute FrozenArray<DOMString> highEntropyDirectArrayDomString;
 
+    // [HighEntropy=Direct] methods
+    [HighEntropy=Direct,MeasureAs=TestMethodHighEntropyDirectNoArgsRetBoolean] boolean highEntropyDirectBoolean();
+
     // with [CEReactions] for not overloaded method
     [CEReactions] void ceReactionsNotOverloadedMethod(boolean arg);
     // with and without [CEReactions] for overloaded method

third_party/blink/renderer/bindings/tests/results/core/v8_test_object.cc

@@ -7966,6 +7966,15 @@ static void HighEntropyMethodWithMeasureAsMethod(const v8::FunctionCallbackInfo<
   impl->highEntropyMethodWithMeasureAs();
 }
 
+static void HighEntropyDirectBooleanMethod(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  TestObject* impl = V8TestObject::ToImpl(info.Holder());
+
+  ExecutionContext* execution_context = ExecutionContext::ForRelevantRealm(info);
+  bool result = impl->highEntropyDirectBoolean();
+  Dactyloscoper::RecordDirectSurface(execution_context, WebFeature::kTestMethodHighEntropyDirectNoArgsRetBoolean, result);
+  V8SetReturnValueBool(info, result);
+}
+
 static void CeReactionsNotOverloadedMethodMethod(const v8::FunctionCallbackInfo<v8::Value>& info) {
   ExceptionState exception_state(info.GetIsolate(), ExceptionState::kExecutionContext, "TestObject", "ceReactionsNotOverloadedMethod");
   CEReactionsScope ce_reactions_scope;
@@ -12579,6 +12588,16 @@ void V8TestObject::HighEntropyMethodWithMeasureAsMethodCallback(const v8::Functi
   test_object_v8_internal::HighEntropyMethodWithMeasureAsMethod(info);
 }
 
+void V8TestObject::HighEntropyDirectBooleanMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  BLINK_BINDINGS_TRACE_EVENT("TestObject.highEntropyDirectBoolean");
+  RUNTIME_CALL_TIMER_SCOPE_DISABLED_BY_DEFAULT(info.GetIsolate(), "Blink_TestObject_highEntropyDirectBoolean");
+
+  ExecutionContext* execution_context_for_measurement = CurrentExecutionContext(info.GetIsolate());
+  UseCounter::Count(execution_context_for_measurement, WebFeature::kTestMethodHighEntropyDirectNoArgsRetBoolean);
+  Dactyloscoper::Record(execution_context_for_measurement, WebFeature::kTestMethodHighEntropyDirectNoArgsRetBoolean);
+  test_object_v8_internal::HighEntropyDirectBooleanMethod(info);
+}
+
 void V8TestObject::CeReactionsNotOverloadedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
   BLINK_BINDINGS_TRACE_EVENT("TestObject.ceReactionsNotOverloadedMethod");
   RUNTIME_CALL_TIMER_SCOPE_DISABLED_BY_DEFAULT(info.GetIsolate(), "Blink_TestObject_ceReactionsNotOverloadedMethod");
@@ -13191,6 +13210,7 @@ static constexpr V8DOMConfiguration::MethodConfiguration kV8TestObjectMethods[]
     {"measureAsSameValueOverloadedMethod", V8TestObject::MeasureAsSameValueOverloadedMethodMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
     {"highEntropyMethodWithMeasure", V8TestObject::HighEntropyMethodWithMeasureMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
     {"highEntropyMethodWithMeasureAs", V8TestObject::HighEntropyMethodWithMeasureAsMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
+    {"highEntropyDirectBoolean", V8TestObject::HighEntropyDirectBooleanMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
     {"ceReactionsNotOverloadedMethod", V8TestObject::CeReactionsNotOverloadedMethodMethodCallback, 1, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
     {"ceReactionsOverloadedMethod", V8TestObject::CeReactionsOverloadedMethodMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},
     {"deprecateAsMeasureAsSameValueOverloadedMethod", V8TestObject::DeprecateAsMeasureAsSameValueOverloadedMethodMethodCallback, 0, v8::None, V8DOMConfiguration::kOnPrototype, V8DOMConfiguration::kCheckHolder, V8DOMConfiguration::kDoNotCheckAccess, V8DOMConfiguration::kHasSideEffect, V8DOMConfiguration::kAllWorlds},

third_party/blink/renderer/bindings/tests/results/core/v8_test_object.h

@@ -542,6 +542,7 @@ class V8TestObject {
   CORE_EXPORT static void MeasureAsSameValueOverloadedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
   CORE_EXPORT static void HighEntropyMethodWithMeasureMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
   CORE_EXPORT static void HighEntropyMethodWithMeasureAsMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
+  CORE_EXPORT static void HighEntropyDirectBooleanMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
   CORE_EXPORT static void CeReactionsNotOverloadedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
   CORE_EXPORT static void CeReactionsOverloadedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);
   CORE_EXPORT static void DeprecateAsMeasureAsSameValueOverloadedMethodMethodCallback(const v8::FunctionCallbackInfo<v8::Value>&);