Model each Dart library as its own ScriptState when devtools are enabled.

Source/bindings/dart/DartHandleProxy.cpp

Index: Source/bindings/dart/DartHandleProxy.cpp
diff --git a/Source/bindings/dart/DartHandleProxy.cpp b/Source/bindings/dart/DartHandleProxy.cpp
index 9cc0ed0a4c4b5617f94635ba583ee4a6b75c739b..a17fb8d6e2a0c65037cc6692a76d267cc8a50743 100644
--- a/Source/bindings/dart/DartHandleProxy.cpp
+++ b/Source/bindings/dart/DartHandleProxy.cpp
@@ -58,22 +58,24 @@ DartScriptValue* readPointerFromProxy(v8::Handle<v8::Value> proxy)
     return static_cast<DartScriptValue*>(pointer);
 }
 
-DartScopes::DartScopes(v8::Local<v8::Object> v8Handle) :
+DartScopes::DartScopes(v8::Local<v8::Object> v8Handle, bool disableBreak) :
     scriptValue(readPointerFromProxy(v8Handle)),
-    scope(scriptValue->isolate())
+    scope(scriptValue->isolate()),
+    disableBreak(disableBreak)
 {
     ASSERT(scriptValue->isIsolateAlive());
     handle = scriptValue->value();
-    previousPauseInfo = Dart_GetExceptionPauseInfo();
-    // FIXME: it is not clear this is the right long term solution but for
-    // now we prevent pausing on exceptions when executing Dart code to
-    // avoid crashing when handling an exception triggers an exception.
-    Dart_SetExceptionPauseInfo(kNoPauseOnExceptions);
+    if (disableBreak) {
+        previousPauseInfo = Dart_GetExceptionPauseInfo();
+        Dart_SetExceptionPauseInfo(kNoPauseOnExceptions);
+    }
 }
 
 DartScopes::~DartScopes()
 {
-    Dart_SetExceptionPauseInfo(previousPauseInfo);
+    if (disableBreak) {
+        Dart_SetExceptionPauseInfo(previousPauseInfo);
+    }
 }
 
 
@@ -1085,4 +1087,52 @@ v8::Handle<v8::Value> DartHandleProxy::createLocalScopeProxy(Dart_Handle localVa
     return proxy;
 }
 
+v8::Handle<v8::Value> DartHandleProxy::evaluate(Dart_Handle target, Dart_Handle expression, Dart_Handle localVariables)
+{
+    ASSERT(Dart_IsList(localVariables) || Dart_IsNull(localVariables));
+    intptr_t localVariablesLength = 0;
+    Dart_ListLength(localVariables, &localVariablesLength);
+
+    Dart_Handle wrapExpressionArgs[2] = { expression, localVariables };
+    Dart_Handle exception = 0;
+    bool ret = DartUtilities::dartToBool(DartUtilities::invokeUtilsMethod("isJsExpression", 1, &expression), exception);
+    ASSERT(!exception);
+    if (ret) {
+        // FIXME(dartbug.com/13468): remove this hacky fallback of invoking JS
+        // code when we believe a JS code fragment generated by the chrome
+        // developer tools was passed to us rather than a fragment of true
+        // Dart code.
+        ASSERT(!v8::Context::GetCurrent().IsEmpty());
+        v8::Handle<v8::Value> result = V8ScriptRunner::compileAndRunInternalScript(V8Converter::stringToV8(expression), v8::Isolate::GetCurrent());
+        return result;
+    }
+
+    Dart_Handle wrappedExpressionTuple =
+        DartUtilities::invokeUtilsMethod("wrapExpressionAsClosure", 2, wrapExpressionArgs);
+    ASSERT(Dart_IsList(wrappedExpressionTuple));
+    Dart_Handle wrappedExpression = Dart_ListGetAt(wrappedExpressionTuple, 0);
+    Dart_Handle wrappedExpressionArgs = Dart_ListGetAt(wrappedExpressionTuple, 1);
+
+    ASSERT(Dart_IsString(wrappedExpression));
+    Dart_Handle closure = Dart_EvaluateExpr(target, wrappedExpression);
+    // There was a parse error. FIXME: consider cleaning up the line numbers in
+    // the error message.
+    if (Dart_IsError(closure))
+        return V8ThrowException::throwError(v8::String::New(Dart_GetError(closure)));
+
+    // Invoke the closure passing in the expression arguments specified by
+    // wrappedExpressionTuple.
+    ASSERT(Dart_IsClosure(closure));
+    intptr_t length = 0;
+    Dart_ListLength(wrappedExpressionArgs, &length);
+    Vector<Dart_Handle> dartFunctionArgs;
+    for (uint32_t i = 0; i < length; i ++)
+        dartFunctionArgs.append(Dart_ListGetAt(wrappedExpressionArgs, i));
+
+    Dart_Handle result = Dart_InvokeClosure(closure, dartFunctionArgs.size(), dartFunctionArgs.data());
+    if (Dart_IsError(result))
+        return V8ThrowException::throwError(v8::String::New(Dart_GetError(result)));
+    return DartHandleProxy::create(result);
+}
+
 }