[DevTools] Debugger::currentCallFrames returns array instead linked list

We can return array instead linked list since V8JavaScriptCallFrame wrapper was removed.
Method callFrameByIndex was removed because we can use currentCallFrames instead: cached when DevTools is paused and with getter when we check stack trace for DOM breakpoint.

BUG=595206
R=dgozman@chromium.org

Review URL: https://codereview.chromium.org/1838683002

Cr-Commit-Position: refs/heads/master@{#383448}

9 files changed, 92 insertions, 162 deletions

diff --git a/third_party/WebKit/LayoutTests/inspector-protocol/debugger/access-obsolete-frame.html b/third_party/WebKit/LayoutTests/inspector-protocol/debugger/access-obsolete-frame.html
index b4bb0e5..b614228 100644
--- a/third_party/WebKit/LayoutTests/inspector-protocol/debugger/access-obsolete-frame.html
+++ b/third_party/WebKit/LayoutTests/inspector-protocol/debugger/access-obsolete-frame.html
@@ -60,7 +60,7 @@ function test()
     function logErrorResponse(response)
     {
         if (response.error) {
-            if (response.error.message.indexOf("debugger is not on pause") != -1) {
+            if (response.error.message.indexOf("Can only perform operation while paused.") != -1) {
                 InspectorTest.log("PASS, error message as expected");
                 return;
             }
diff --git a/third_party/WebKit/Source/platform/v8_inspector/DebuggerScript.js b/third_party/WebKit/Source/platform/v8_inspector/DebuggerScript.js
index c4992db..cb25482 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/DebuggerScript.js
+++ b/third_party/WebKit/Source/platform/v8_inspector/DebuggerScript.js
@@ -274,41 +274,15 @@ DebuggerScript.setPauseOnExceptionsState = function(newState)
 
 /**
  * @param {!ExecutionState} execState
- * @return {number}
- */
-DebuggerScript.frameCount = function(execState)
-{
-    return execState.frameCount();
-}
-
-/**
- * @param {!ExecutionState} execState
- * @return {!JavaScriptCallFrame|undefined}
- */
-DebuggerScript.currentCallFrame = function(execState)
-{
-    var frameCount = execState.frameCount();
-    var topFrame = undefined;
-    for (var i = frameCount - 1; i >= 0; i--) {
-        var frameMirror = execState.frame(i);
-        topFrame = DebuggerScript._frameMirrorToJSCallFrame(frameMirror, topFrame);
-    }
-    return topFrame;
-}
-
-/**
- * @param {!ExecutionState} execState
- * @param {number} index
- * @return {!JavaScriptCallFrame|undefined}
+ * @param {number} limit
+ * @return {!Array<!JavaScriptCallFrame>}
  */
-DebuggerScript.currentCallFrameByIndex = function(execState, index)
+DebuggerScript.currentCallFrames = function(execState, limit)
 {
-    if (index < 0)
-        return undefined;
-    var frameCount = execState.frameCount();
-    if (index >= frameCount)
-        return undefined;
-    return DebuggerScript._frameMirrorToJSCallFrame(execState.frame(index), undefined);
+    var frames = [];
+    for (var i = 0; i < execState.frameCount() && (!limit || i < limit); ++i)
+        frames.push(DebuggerScript._frameMirrorToJSCallFrame(execState.frame(i)));
+    return frames;
 }
 
 /**
@@ -427,10 +401,9 @@ DebuggerScript.getBreakpointNumbers = function(eventData)
 // asynchronous call stacks. Thus, when possible, initialize the data lazily.
 /**
  * @param {!FrameMirror} frameMirror
- * @param {!JavaScriptCallFrame|undefined} callerFrame
  * @return {!JavaScriptCallFrame}
  */
-DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror, callerFrame)
+DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror)
 {
     // Stuff that can not be initialized lazily (i.e. valid while paused with a valid break_id).
     // The frameMirror and scopeMirror can be accessed only while paused on the debugger.
@@ -664,7 +637,6 @@ DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror, callerFrame)
         "column": column,
         "thisObject": thisObject,
         "evaluate": evaluate,
-        "caller": callerFrame,
         "restart": restart,
         "setVariableValue": setVariableValue,
         "isAtReturn": isAtReturn,
diff --git a/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.cpp b/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.cpp
index 59b292a..5c216f6 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.cpp
+++ b/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.cpp
@@ -47,16 +47,6 @@ JavaScriptCallFrame::~JavaScriptCallFrame()
 {
 }
 
-PassOwnPtr<JavaScriptCallFrame> JavaScriptCallFrame::caller()
-{
-    v8::HandleScope handleScope(m_isolate);
-    v8::Local<v8::Context> debuggerContext = v8::Local<v8::Context>::New(m_isolate, m_debuggerContext);
-    v8::Local<v8::Value> callerFrame = v8::Local<v8::Object>::New(m_isolate, m_callFrame)->Get(toV8StringInternalized(m_isolate, "caller"));
-    if (callerFrame.IsEmpty() || !callerFrame->IsObject())
-        return 0;
-    return JavaScriptCallFrame::create(debuggerContext, v8::Local<v8::Object>::Cast(callerFrame));
-}
-
 int JavaScriptCallFrame::callV8FunctionReturnInt(const char* name) const
 {
     v8::HandleScope handleScope(m_isolate);
diff --git a/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.h b/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.h
index 46e6aab..f89576a 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.h
+++ b/third_party/WebKit/Source/platform/v8_inspector/JavaScriptCallFrame.h
@@ -46,8 +46,6 @@ public:
     }
     ~JavaScriptCallFrame();
 
-    PassOwnPtr<JavaScriptCallFrame> caller();
-
     int sourceID() const;
     int line() const;
     int column() const;
@@ -70,6 +68,8 @@ private:
     v8::Global<v8::FunctionTemplate> m_wrapperTemplate;
 };
 
+using JavaScriptCallFrames = Vector<OwnPtr<JavaScriptCallFrame>>;
+
 } // namespace blink
 
 #endif // JavaScriptCallFrame_h
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.cpp b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.cpp
index e4d02ed..72ada62 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.cpp
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.cpp
@@ -243,7 +243,8 @@ void V8DebuggerAgentImpl::disable(ErrorString*)
 
     debugger().removeDebuggerAgent(m_contextGroupId);
     m_pausedContext.Reset();
-    m_currentCallStack.clear();
+    JavaScriptCallFrames emptyCallFrames;
+    m_pausedCallFrames.swap(emptyCallFrames);
     m_scripts.clear();
     m_blackboxedPositions.clear();
     m_breakpointIdToDebuggerBreakpointIds.clear();
@@ -484,30 +485,28 @@ void V8DebuggerAgentImpl::getBacktrace(ErrorString* errorString, OwnPtr<Array<Ca
 {
     if (!assertPaused(errorString))
         return;
-    m_currentCallStack = debugger().currentCallFrames();
+    m_pausedCallFrames = debugger().currentCallFrames();
     *callFrames = currentCallFrames(errorString);
     if (!*callFrames)
         return;
     *asyncStackTrace = currentAsyncStackTrace();
 }
 
-bool V8DebuggerAgentImpl::isCallStackEmptyOrBlackboxed()
+bool V8DebuggerAgentImpl::isCurrentCallStackEmptyOrBlackboxed()
 {
     ASSERT(enabled());
-    for (int index = 0; ; ++index) {
-        OwnPtr<JavaScriptCallFrame> frame = debugger().callFrame(index);
-        if (!frame)
-            break;
-        if (!isCallFrameWithUnknownScriptOrBlackboxed(frame.get()))
+    JavaScriptCallFrames callFrames = debugger().currentCallFrames();
+    for (size_t index = 0; index < callFrames.size(); ++index) {
+        if (!isCallFrameWithUnknownScriptOrBlackboxed(callFrames[index].get()))
             return false;
     }
     return true;
 }
 
-bool V8DebuggerAgentImpl::isTopCallFrameBlackboxed()
+bool V8DebuggerAgentImpl::isTopPausedCallFrameBlackboxed()
 {
     ASSERT(enabled());
-    return isCallFrameWithUnknownScriptOrBlackboxed(debugger().callFrame(0).get());
+    return isCallFrameWithUnknownScriptOrBlackboxed(m_pausedCallFrames.size() ? m_pausedCallFrames[0].get() : nullptr);
 }
 
 bool V8DebuggerAgentImpl::isCallFrameWithUnknownScriptOrBlackboxed(JavaScriptCallFrame* frame)
@@ -530,16 +529,16 @@ bool V8DebuggerAgentImpl::isCallFrameWithUnknownScriptOrBlackboxed(JavaScriptCal
     return std::distance(ranges->begin(), itRange) % 2;
 }
 
-V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipExceptionPause()
+V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipExceptionPause(JavaScriptCallFrame* topCallFrame)
 {
     if (m_steppingFromFramework)
         return RequestNoSkip;
-    if (isTopCallFrameBlackboxed())
+    if (isCallFrameWithUnknownScriptOrBlackboxed(topCallFrame))
         return RequestContinue;
     return RequestNoSkip;
 }
 
-V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipStepPause()
+V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipStepPause(JavaScriptCallFrame* topCallFrame)
 {
     if (m_steppingFromFramework)
         return RequestNoSkip;
@@ -550,7 +549,7 @@ V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipStepPause()
             return RequestStepOut;
     }
 
-    if (!isTopCallFrameBlackboxed())
+    if (!isCallFrameWithUnknownScriptOrBlackboxed(topCallFrame))
         return RequestNoSkip;
 
     if (m_skippedStepFrameCount >= maxSkipStepFrameCount)
@@ -616,7 +615,7 @@ void V8DebuggerAgentImpl::setScriptSource(ErrorString* errorString,
 {
     if (!checkEnabled(errorString))
         return;
-    if (!debugger().setScriptSource(scriptId, newContent, preview.fromMaybe(false), errorString, optOutCompileError, &m_currentCallStack, stackChanged))
+    if (!debugger().setScriptSource(scriptId, newContent, preview.fromMaybe(false), errorString, optOutCompileError, &m_pausedCallFrames, stackChanged))
         return;
 
     OwnPtr<Array<CallFrame>> callFrames = currentCallFrames(errorString);
@@ -636,10 +635,8 @@ void V8DebuggerAgentImpl::restartFrame(ErrorString* errorString,
     OwnPtr<Array<CallFrame>>* newCallFrames,
     Maybe<StackTrace>* asyncStackTrace)
 {
-    if (!isPaused() || !m_currentCallStack) {
-        *errorString = "Attempt to access call frame when debugger is not on pause";
+    if (!assertPaused(errorString))
         return;
-    }
     OwnPtr<RemoteCallFrameId> remoteId = RemoteCallFrameId::parse(errorString, callFrameId);
     if (!remoteId)
         return;
@@ -652,19 +649,19 @@ void V8DebuggerAgentImpl::restartFrame(ErrorString* errorString,
 
     v8::TryCatch tryCatch(m_isolate);
 
-    OwnPtr<JavaScriptCallFrame> javaScriptCallFrame = debugger().callFrame(remoteId->frameOrdinal());
-    if (!javaScriptCallFrame) {
+    size_t frameOrdinal = static_cast<size_t>(remoteId->frameOrdinal());
+    if (frameOrdinal >= m_pausedCallFrames.size()) {
         *errorString = "Could not find call frame with given id";
         return;
     }
     v8::Local<v8::Value> resultValue;
     v8::Local<v8::Boolean> result;
-    if (!javaScriptCallFrame->restart().ToLocal(&resultValue) || tryCatch.HasCaught() || !resultValue->ToBoolean(localContext).ToLocal(&result) || !result->Value()) {
+    if (!m_pausedCallFrames[frameOrdinal].get()->restart().ToLocal(&resultValue) || tryCatch.HasCaught() || !resultValue->ToBoolean(localContext).ToLocal(&result) || !result->Value()) {
         *errorString = "Internal error";
         return;
     }
 
-    m_currentCallStack = debugger().currentCallFrames();
+    m_pausedCallFrames = debugger().currentCallFrames();
 
     *newCallFrames = currentCallFrames(errorString);
     if (!*newCallFrames)
@@ -892,13 +889,13 @@ void V8DebuggerAgentImpl::stepOver(ErrorString* errorString)
     if (!assertPaused(errorString))
         return;
     // StepOver at function return point should fallback to StepInto.
-    OwnPtr<JavaScriptCallFrame> frame = debugger().callFrame(0);
+    JavaScriptCallFrame* frame = m_pausedCallFrames.size() ? m_pausedCallFrames[0].get() : nullptr;
     if (frame && frame->isAtReturn()) {
         stepInto(errorString);
         return;
     }
     m_scheduledDebuggerStep = StepOver;
-    m_steppingFromFramework = isTopCallFrameBlackboxed();
+    m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
     m_injectedScriptManager->releaseObjectGroup(V8DebuggerAgentImpl::backtraceObjectGroup);
     debugger().stepOverStatement();
 }
@@ -908,7 +905,7 @@ void V8DebuggerAgentImpl::stepInto(ErrorString* errorString)
     if (!assertPaused(errorString))
         return;
     m_scheduledDebuggerStep = StepInto;
-    m_steppingFromFramework = isTopCallFrameBlackboxed();
+    m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
     m_injectedScriptManager->releaseObjectGroup(V8DebuggerAgentImpl::backtraceObjectGroup);
     debugger().stepIntoStatement();
 }
@@ -920,7 +917,7 @@ void V8DebuggerAgentImpl::stepOut(ErrorString* errorString)
     m_scheduledDebuggerStep = StepOut;
     m_skipNextDebuggerStepOut = false;
     m_recursionLevelForStepOut = 1;
-    m_steppingFromFramework = isTopCallFrameBlackboxed();
+    m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
     m_injectedScriptManager->releaseObjectGroup(V8DebuggerAgentImpl::backtraceObjectGroup);
     debugger().stepOutOfFunction();
 }
@@ -977,10 +974,8 @@ void V8DebuggerAgentImpl::evaluateOnCallFrame(ErrorString* errorString,
     Maybe<bool>* wasThrown,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails)
 {
-    if (!isPaused() || !m_currentCallStack) {
-        *errorString = "Attempt to access callframe when debugger is not on pause";
+    if (!assertPaused(errorString))
         return;
-    }
     OwnPtr<RemoteCallFrameId> remoteId = RemoteCallFrameId::parse(errorString, callFrameId);
     if (!remoteId)
         return;
@@ -995,8 +990,8 @@ void V8DebuggerAgentImpl::evaluateOnCallFrame(ErrorString* errorString,
         return;
     }
 
-    OwnPtr<JavaScriptCallFrame> javaScriptCallFrame = debugger().callFrame(remoteId->frameOrdinal());
-    if (!javaScriptCallFrame) {
+    size_t frameOrdinal = static_cast<size_t>(remoteId->frameOrdinal());
+    if (frameOrdinal >= m_pausedCallFrames.size()) {
         *errorString = "Could not find call frame with given id";
         return;
     }
@@ -1009,7 +1004,7 @@ void V8DebuggerAgentImpl::evaluateOnCallFrame(ErrorString* errorString,
 
     v8::TryCatch tryCatch(injectedScript->isolate());
 
-    v8::MaybeLocal<v8::Value> maybeResultValue = javaScriptCallFrame->evaluate(toV8String(injectedScript->isolate(), expression));
+    v8::MaybeLocal<v8::Value> maybeResultValue = m_pausedCallFrames[frameOrdinal].get()->evaluate(toV8String(injectedScript->isolate(), expression));
 
     // InjectedScript may be gone after any evaluate call - find it again.
     injectedScript = m_injectedScriptManager->findInjectedScript(errorString, remoteId.get());
@@ -1035,10 +1030,8 @@ void V8DebuggerAgentImpl::setVariableValue(ErrorString* errorString,
 {
     if (!checkEnabled(errorString))
         return;
-    if (!isPaused() || !m_currentCallStack) {
-        *errorString = "Attempt to access callframe when debugger is not on pause";
+    if (!assertPaused(errorString))
         return;
-    }
     OwnPtr<RemoteCallFrameId> remoteId = RemoteCallFrameId::parse(errorString, callFrameId);
     if (!remoteId)
         return;
@@ -1053,12 +1046,12 @@ void V8DebuggerAgentImpl::setVariableValue(ErrorString* errorString,
     if (!injectedScript->resolveCallArgument(errorString, newValueArgument.get()).ToLocal(&newValue))
         return;
 
-    OwnPtr<JavaScriptCallFrame> javaScriptCallFrame = debugger().callFrame(remoteId->frameOrdinal());
-    if (!javaScriptCallFrame) {
+    size_t frameOrdinal = static_cast<size_t>(remoteId->frameOrdinal());
+    if (frameOrdinal >= m_pausedCallFrames.size()) {
         *errorString = "Could not find call frame with given id";
         return;
     }
-    v8::MaybeLocal<v8::Value> result = javaScriptCallFrame->setVariableValue(scopeNumber, toV8String(m_isolate, variableName), newValue);
+    v8::MaybeLocal<v8::Value> result = m_pausedCallFrames[frameOrdinal].get()->setVariableValue(scopeNumber, toV8String(m_isolate, variableName), newValue);
     if (tryCatch.HasCaught() || result.IsEmpty()) {
         *errorString = "Internal error";
         return;
@@ -1351,7 +1344,7 @@ void V8DebuggerAgentImpl::changeJavaScriptRecursionLevel(int step)
 
 PassOwnPtr<Array<CallFrame>> V8DebuggerAgentImpl::currentCallFrames(ErrorString* errorString)
 {
-    if (m_pausedContext.IsEmpty() || !m_currentCallStack)
+    if (m_pausedContext.IsEmpty() || !m_pausedCallFrames.size())
         return Array<CallFrame>::create();
     InjectedScript* injectedScript = m_injectedScriptManager->injectedScriptFor(m_pausedContext.Get(m_isolate));
     if (!injectedScript) {
@@ -1364,16 +1357,15 @@ PassOwnPtr<Array<CallFrame>> V8DebuggerAgentImpl::currentCallFrames(ErrorString*
     v8::Local<v8::Context> context = injectedScript->context();
     v8::Context::Scope contextScope(context);
 
-    JavaScriptCallFrame* currentCallFrame = m_currentCallStack.get();
-    int callFrameIndex = 0;
-    OwnPtr<JavaScriptCallFrame> currentCallFrameOwner;
     v8::Local<v8::Array> objects = v8::Array::New(isolate);
-    while (currentCallFrame) {
+    for (size_t frameOrdinal = 0; frameOrdinal < m_pausedCallFrames.size(); ++frameOrdinal) {
+        JavaScriptCallFrame* currentCallFrame = m_pausedCallFrames[frameOrdinal].get();
+
         v8::Local<v8::Object> details = currentCallFrame->details();
         if (hasInternalError(errorString, details.IsEmpty()))
             return Array<CallFrame>::create();
 
-        String16 callFrameId = RemoteCallFrameId::serialize(injectedScript->contextId(), callFrameIndex);
+        String16 callFrameId = RemoteCallFrameId::serialize(injectedScript->contextId(), frameOrdinal);
         if (hasInternalError(errorString, !details->Set(context, toV8StringInternalized(isolate, "callFrameId"), toV8String(isolate, callFrameId)).FromMaybe(false)))
             return Array<CallFrame>::create();
 
@@ -1392,12 +1384,8 @@ PassOwnPtr<Array<CallFrame>> V8DebuggerAgentImpl::currentCallFrames(ErrorString*
                 return Array<CallFrame>::create();
         }
 
-        if (hasInternalError(errorString, !objects->Set(context, callFrameIndex, details).FromMaybe(false)))
+        if (hasInternalError(errorString, !objects->Set(context, frameOrdinal, details).FromMaybe(false)))
             return Array<CallFrame>::create();
-
-        currentCallFrameOwner = currentCallFrame->caller();
-        currentCallFrame = currentCallFrameOwner.get();
-        ++callFrameIndex;
     }
 
     protocol::ErrorSupport errorSupport;
@@ -1486,31 +1474,34 @@ void V8DebuggerAgentImpl::didParseSource(const V8DebuggerParsedScript& parsedScr
     }
 }
 
-V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::didPause(v8::Local<v8::Context> context, PassOwnPtr<JavaScriptCallFrame> callFrames, v8::Local<v8::Value> exception, const protocol::Vector<String16>& hitBreakpoints, bool isPromiseRejection)
+V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::didPause(v8::Local<v8::Context> context, v8::Local<v8::Value> exception, const protocol::Vector<String16>& hitBreakpoints, bool isPromiseRejection)
 {
+    JavaScriptCallFrames callFrames = debugger().currentCallFrames(1);
+    JavaScriptCallFrame* topCallFrame = callFrames.size() > 0 ? callFrames[0].get() : nullptr;
+
     V8DebuggerAgentImpl::SkipPauseRequest result;
     if (m_skipAllPauses)
         result = RequestContinue;
     else if (!hitBreakpoints.isEmpty())
         result = RequestNoSkip; // Don't skip explicit breakpoints even if set in frameworks.
     else if (!exception.IsEmpty())
-        result = shouldSkipExceptionPause();
+        result = shouldSkipExceptionPause(topCallFrame);
     else if (m_scheduledDebuggerStep != NoStep || m_javaScriptPauseScheduled || m_pausingOnNativeEvent)
-        result = shouldSkipStepPause();
+        result = shouldSkipStepPause(topCallFrame);
     else
         result = RequestNoSkip;
 
     m_skipNextDebuggerStepOut = false;
     if (result != RequestNoSkip)
         return result;
-
     // Skip pauses inside V8 internal scripts and on syntax errors.
-    if (!callFrames)
+    if (!topCallFrame)
         return RequestContinue;
 
     ASSERT(m_pausedContext.IsEmpty());
+    callFrames = debugger().currentCallFrames();
+    m_pausedCallFrames.swap(callFrames);
     m_pausedContext.Reset(m_isolate, context);
-    m_currentCallStack = callFrames;
     v8::HandleScope handles(m_isolate);
 
     if (!exception.IsEmpty()) {
@@ -1565,7 +1556,8 @@ V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::didPause(v8::Local<v8
 void V8DebuggerAgentImpl::didContinue()
 {
     m_pausedContext.Reset();
-    m_currentCallStack.clear();
+    JavaScriptCallFrames emptyCallFrames;
+    m_pausedCallFrames.swap(emptyCallFrames);
     clearBreakDetails();
     m_frontend->resumed();
 }
@@ -1578,7 +1570,7 @@ bool V8DebuggerAgentImpl::canBreakProgram()
 void V8DebuggerAgentImpl::breakProgram(const String16& breakReason, PassOwnPtr<protocol::DictionaryValue> data)
 {
     ASSERT(enabled());
-    if (m_skipAllPauses || !m_pausedContext.IsEmpty() || isCallStackEmptyOrBlackboxed() || !debugger().breakpointsActivated())
+    if (m_skipAllPauses || !m_pausedContext.IsEmpty() || isCurrentCallStackEmptyOrBlackboxed() || !debugger().breakpointsActivated())
         return;
     m_breakReason = breakReason;
     m_breakAuxData = data;
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.h b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.h
index 0a47745..d6e705a 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.h
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerAgentImpl.h
@@ -163,7 +163,7 @@ public:
     void reset();
 
     // Interface for V8DebuggerImpl
-    SkipPauseRequest didPause(v8::Local<v8::Context>, PassOwnPtr<JavaScriptCallFrame> callFrames, v8::Local<v8::Value> exception, const protocol::Vector<String16>& hitBreakpoints, bool isPromiseRejection);
+    SkipPauseRequest didPause(v8::Local<v8::Context>, v8::Local<v8::Value> exception, const protocol::Vector<String16>& hitBreakpoints, bool isPromiseRejection);
     void didContinue();
     void didParseSource(const V8DebuggerParsedScript&);
     bool v8AsyncTaskEventsEnabled() const;
@@ -177,8 +177,8 @@ private:
     bool checkEnabled(ErrorString*);
     void enable();
 
-    SkipPauseRequest shouldSkipExceptionPause();
-    SkipPauseRequest shouldSkipStepPause();
+    SkipPauseRequest shouldSkipExceptionPause(JavaScriptCallFrame* topCallFrame);
+    SkipPauseRequest shouldSkipStepPause(JavaScriptCallFrame* topCallFrame);
 
     void schedulePauseOnNextStatementIfSteppingInto();
 
@@ -198,8 +198,8 @@ private:
     bool assertPaused(ErrorString*);
     void clearBreakDetails();
 
-    bool isCallStackEmptyOrBlackboxed();
-    bool isTopCallFrameBlackboxed();
+    bool isCurrentCallStackEmptyOrBlackboxed();
+    bool isTopPausedCallFrameBlackboxed();
     bool isCallFrameWithUnknownScriptOrBlackboxed(JavaScriptCallFrame*);
 
     void internalSetAsyncCallStackDepth(int);
@@ -225,7 +225,7 @@ private:
     protocol::Frontend::Debugger* m_frontend;
     v8::Isolate* m_isolate;
     v8::Global<v8::Context> m_pausedContext;
-    OwnPtr<JavaScriptCallFrame> m_currentCallStack;
+    JavaScriptCallFrames m_pausedCallFrames;
     ScriptsMap m_scripts;
     BreakpointIdToDebuggerBreakpointIdsMap m_breakpointIdToDebuggerBreakpointIds;
     DebugServerBreakpointToBreakpointIdAndSourceMap m_serverBreakpoints;
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.cpp b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.cpp
index feb0f4e..750f6c2 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.cpp
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.cpp
@@ -33,7 +33,6 @@
 #include "platform/inspector_protocol/Values.h"
 #include "platform/v8_inspector/Atomics.h"
 #include "platform/v8_inspector/DebuggerScript.h"
-#include "platform/v8_inspector/JavaScriptCallFrame.h"
 #include "platform/v8_inspector/ScriptBreakpoint.h"
 #include "platform/v8_inspector/V8DebuggerAgentImpl.h"
 #include "platform/v8_inspector/V8RuntimeAgentImpl.h"
@@ -396,7 +395,7 @@ void V8DebuggerImpl::clearStepping()
     callDebuggerMethod("clearStepping", 0, argv);
 }
 
-bool V8DebuggerImpl::setScriptSource(const String16& sourceID, const String16& newContent, bool preview, ErrorString* error, Maybe<protocol::Debugger::SetScriptSourceError>* errorData, OwnPtr<JavaScriptCallFrame>* newCallFrames, Maybe<bool>* stackChanged)
+bool V8DebuggerImpl::setScriptSource(const String16& sourceID, const String16& newContent, bool preview, ErrorString* error, Maybe<protocol::Debugger::SetScriptSourceError>* errorData, JavaScriptCallFrames* newCallFrames, Maybe<bool>* stackChanged)
 {
     class EnableLiveEditScope {
     public:
@@ -465,53 +464,33 @@ bool V8DebuggerImpl::setScriptSource(const String16& sourceID, const String16& n
     return false;
 }
 
-int V8DebuggerImpl::frameCount()
-{
-    ASSERT(isPaused());
-    ASSERT(!m_executionState.IsEmpty());
-    v8::Local<v8::Value> argv[] = { m_executionState };
-    v8::Local<v8::Value> result = callDebuggerMethod("frameCount", WTF_ARRAY_LENGTH(argv), argv).ToLocalChecked();
-    if (result->IsInt32())
-        return result->Int32Value();
-    return 0;
-}
-
-PassOwnPtr<JavaScriptCallFrame> V8DebuggerImpl::currentCallFrames()
+JavaScriptCallFrames V8DebuggerImpl::currentCallFrames(int limit)
 {
     if (!m_isolate->InContext())
-        return nullptr;
-    v8::Local<v8::Value> currentCallFrameV8;
+        return JavaScriptCallFrames();
+    v8::Local<v8::Value> currentCallFramesV8;
     if (m_executionState.IsEmpty()) {
-        v8::Local<v8::Function> currentCallFrameFunction = v8::Local<v8::Function>::Cast(m_debuggerScript.Get(m_isolate)->Get(v8InternalizedString("currentCallFrame")));
-        currentCallFrameV8 = v8::Debug::Call(debuggerContext(), currentCallFrameFunction).ToLocalChecked();
+        v8::Local<v8::Function> currentCallFramesFunction = v8::Local<v8::Function>::Cast(m_debuggerScript.Get(m_isolate)->Get(v8InternalizedString("currentCallFrames")));
+        currentCallFramesV8 = v8::Debug::Call(debuggerContext(), currentCallFramesFunction, v8::Integer::New(m_isolate, limit)).ToLocalChecked();
     } else {
-        v8::Local<v8::Value> argv[] = { m_executionState };
-        currentCallFrameV8 = callDebuggerMethod("currentCallFrame", WTF_ARRAY_LENGTH(argv), argv).ToLocalChecked();
+        v8::Local<v8::Value> argv[] = { m_executionState, v8::Integer::New(m_isolate, limit) };
+        currentCallFramesV8 = callDebuggerMethod("currentCallFrames", WTF_ARRAY_LENGTH(argv), argv).ToLocalChecked();
     }
-    ASSERT(!currentCallFrameV8.IsEmpty());
-    if (!currentCallFrameV8->IsObject())
-        return nullptr;
-    return JavaScriptCallFrame::create(debuggerContext(), v8::Local<v8::Object>::Cast(currentCallFrameV8));
-}
-
-PassOwnPtr<JavaScriptCallFrame> V8DebuggerImpl::callFrame(int index)
-{
-    if (!m_isolate->InContext())
-        return nullptr;
-    v8::HandleScope handleScope(m_isolate);
-
-    v8::Local<v8::Value> currentCallFrameV8;
-    if (m_executionState.IsEmpty()) {
-        v8::Local<v8::Function> currentCallFrameFunction = v8::Local<v8::Function>::Cast(m_debuggerScript.Get(m_isolate)->Get(v8InternalizedString("currentCallFrameByIndex")));
-        currentCallFrameV8 = v8::Debug::Call(debuggerContext(), currentCallFrameFunction, v8::Integer::New(m_isolate, index)).ToLocalChecked();
-    } else {
-        v8::Local<v8::Value> argv[] = { m_executionState, v8::Integer::New(m_isolate, index) };
-        currentCallFrameV8 = callDebuggerMethod("currentCallFrameByIndex", WTF_ARRAY_LENGTH(argv), argv).ToLocalChecked();
+    ASSERT(!currentCallFramesV8.IsEmpty());
+    if (!currentCallFramesV8->IsArray())
+        return JavaScriptCallFrames();
+    v8::Local<v8::Array> callFramesArray = currentCallFramesV8.As<v8::Array>();
+    JavaScriptCallFrames callFrames;
+    for (size_t i = 0; i < callFramesArray->Length(); ++i) {
+        v8::Local<v8::Value> callFrameValue;
+        if (!callFramesArray->Get(debuggerContext(), i).ToLocal(&callFrameValue))
+            return JavaScriptCallFrames();
+        if (!callFrameValue->IsObject())
+            return JavaScriptCallFrames();
+        v8::Local<v8::Object> callFrameObject = callFrameValue.As<v8::Object>();
+        callFrames.append(JavaScriptCallFrame::create(debuggerContext(), v8::Local<v8::Object>::Cast(callFrameObject)));
     }
-    ASSERT(!currentCallFrameV8.IsEmpty());
-    if (!currentCallFrameV8->IsObject())
-        return nullptr;
-    return JavaScriptCallFrame::create(debuggerContext(), v8::Local<v8::Object>::Cast(currentCallFrameV8));
+    return callFrames;
 }
 
 static V8DebuggerImpl* toV8DebuggerImpl(v8::Local<v8::Value> data)
@@ -552,7 +531,7 @@ void V8DebuggerImpl::handleProgramBreak(v8::Local<v8::Context> pausedContext, v8
 
     m_pausedContext = pausedContext;
     m_executionState = executionState;
-    V8DebuggerAgentImpl::SkipPauseRequest result = agent->didPause(pausedContext, currentCallFrames(), exception, breakpointIds, isPromiseRejection);
+    V8DebuggerAgentImpl::SkipPauseRequest result = agent->didPause(pausedContext, exception, breakpointIds, isPromiseRejection);
     if (result == V8DebuggerAgentImpl::RequestNoSkip) {
         m_runningNestedMessageLoop = true;
         int groupId = getGroupId(pausedContext);
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.h b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.h
index 83213ec..0a96e8e09 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.h
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8DebuggerImpl.h
@@ -32,6 +32,7 @@
 #define V8DebuggerImpl_h
 
 #include "platform/inspector_protocol/TypeBuilder.h"
+#include "platform/v8_inspector/JavaScriptCallFrame.h"
 #include "platform/v8_inspector/V8DebuggerScript.h"
 #include "platform/v8_inspector/public/V8Debugger.h"
 #include "wtf/PassOwnPtr.h"
@@ -43,7 +44,6 @@ namespace blink {
 
 using protocol::Maybe;
 
-class JavaScriptCallFrame;
 struct ScriptBreakpoint;
 class V8DebuggerAgentImpl;
 class V8RuntimeAgentImpl;
@@ -83,10 +83,8 @@ public:
     void stepOutOfFunction();
     void clearStepping();
 
-    bool setScriptSource(const String16& sourceID, const String16& newContent, bool preview, ErrorString*, Maybe<protocol::Debugger::SetScriptSourceError>*, OwnPtr<JavaScriptCallFrame>* newCallFrames, Maybe<bool>* stackChanged);
-    PassOwnPtr<JavaScriptCallFrame> currentCallFrames();
-    PassOwnPtr<JavaScriptCallFrame> callFrame(int index);
-    int frameCount();
+    bool setScriptSource(const String16& sourceID, const String16& newContent, bool preview, ErrorString*, Maybe<protocol::Debugger::SetScriptSourceError>*, JavaScriptCallFrames* newCallFrames, Maybe<bool>* stackChanged);
+    JavaScriptCallFrames currentCallFrames(int limit = 0);
 
     bool isPaused();
     v8::Local<v8::Context> pausedContext() { return m_pausedContext; }
diff --git a/third_party/WebKit/Source/platform/v8_inspector/debugger_script_externs.js b/third_party/WebKit/Source/platform/v8_inspector/debugger_script_externs.js
index 75e7a16..5eebeca 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/debugger_script_externs.js
+++ b/third_party/WebKit/Source/platform/v8_inspector/debugger_script_externs.js
@@ -58,7 +58,6 @@ var JavaScriptCallFrameDetails;
         column: function():number,
         thisObject: !Object,
         evaluate: function(string):*,
-        caller: *,
         restart: function():undefined,
         setVariableValue: function(number, string, *):undefined,
         isAtReturn: boolean,