[inspector] Initial import of v8_inspector.

src/inspector/V8DebuggerAgentImpl.cpp

Index: src/inspector/V8DebuggerAgentImpl.cpp
diff --git a/src/inspector/V8DebuggerAgentImpl.cpp b/src/inspector/V8DebuggerAgentImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6063e560c736e882097ad7d1ef1965453698045a
--- /dev/null
+++ b/src/inspector/V8DebuggerAgentImpl.cpp
@@ -0,0 +1,1249 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/inspector/V8DebuggerAgentImpl.h"
+
+#include "src/inspector/InjectedScript.h"
+#include "src/inspector/InspectedContext.h"
+#include "src/inspector/JavaScriptCallFrame.h"
+#include "src/inspector/RemoteObjectId.h"
+#include "src/inspector/ScriptBreakpoint.h"
+#include "src/inspector/SearchUtil.h"
+#include "src/inspector/StringUtil.h"
+#include "src/inspector/V8Debugger.h"
+#include "src/inspector/V8DebuggerScript.h"
+#include "src/inspector/V8InspectorImpl.h"
+#include "src/inspector/V8InspectorSessionImpl.h"
+#include "src/inspector/V8Regex.h"
+#include "src/inspector/V8RuntimeAgentImpl.h"
+#include "src/inspector/V8StackTraceImpl.h"
+#include "src/inspector/protocol/Protocol.h"
+#include "src/inspector/public/V8InspectorClient.h"
+
+#include <algorithm>
+
+namespace v8_inspector {
+
+using protocol::Array;
+using protocol::Maybe;
+using protocol::Debugger::BreakpointId;
+using protocol::Debugger::CallFrame;
+using protocol::Runtime::ExceptionDetails;
+using protocol::Runtime::ScriptId;
+using protocol::Runtime::StackTrace;
+using protocol::Runtime::RemoteObject;
+
+namespace DebuggerAgentState {
+static const char javaScriptBreakpoints[] = "javaScriptBreakopints";
+static const char pauseOnExceptionsState[] = "pauseOnExceptionsState";
+static const char asyncCallStackDepth[] = "asyncCallStackDepth";
+static const char blackboxPattern[] = "blackboxPattern";
+static const char debuggerEnabled[] = "debuggerEnabled";
+
+// Breakpoint properties.
+static const char url[] = "url";
+static const char isRegex[] = "isRegex";
+static const char lineNumber[] = "lineNumber";
+static const char columnNumber[] = "columnNumber";
+static const char condition[] = "condition";
+static const char skipAllPauses[] = "skipAllPauses";
+
+}  // namespace DebuggerAgentState;
+
+static const int maxSkipStepFrameCount = 128;
+static const char backtraceObjectGroup[] = "backtrace";
+
+static String16 breakpointIdSuffix(
+    V8DebuggerAgentImpl::BreakpointSource source) {
+  switch (source) {
+    case V8DebuggerAgentImpl::UserBreakpointSource:
+      break;
+    case V8DebuggerAgentImpl::DebugCommandBreakpointSource:
+      return ":debug";
+    case V8DebuggerAgentImpl::MonitorCommandBreakpointSource:
+      return ":monitor";
+  }
+  return String16();
+}
+
+static String16 generateBreakpointId(
+    const String16& scriptId, int lineNumber, int columnNumber,
+    V8DebuggerAgentImpl::BreakpointSource source) {
+  return scriptId + ":" + String16::fromInteger(lineNumber) + ":" +
+         String16::fromInteger(columnNumber) + breakpointIdSuffix(source);
+}
+
+static bool positionComparator(const std::pair<int, int>& a,
+                               const std::pair<int, int>& b) {
+  if (a.first != b.first) return a.first < b.first;
+  return a.second < b.second;
+}
+
+static bool hasInternalError(ErrorString* errorString, bool hasError) {
+  if (hasError) *errorString = "Internal error";
+  return hasError;
+}
+
+static std::unique_ptr<protocol::Debugger::Location> buildProtocolLocation(
+    const String16& scriptId, int lineNumber, int columnNumber) {
+  return protocol::Debugger::Location::create()
+      .setScriptId(scriptId)
+      .setLineNumber(lineNumber)
+      .setColumnNumber(columnNumber)
+      .build();
+}
+
+V8DebuggerAgentImpl::V8DebuggerAgentImpl(
+    V8InspectorSessionImpl* session, protocol::FrontendChannel* frontendChannel,
+    protocol::DictionaryValue* state)
+    : m_inspector(session->inspector()),
+      m_debugger(m_inspector->debugger()),
+      m_session(session),
+      m_enabled(false),
+      m_state(state),
+      m_frontend(frontendChannel),
+      m_isolate(m_inspector->isolate()),
+      m_breakReason(protocol::Debugger::Paused::ReasonEnum::Other),
+      m_scheduledDebuggerStep(NoStep),
+      m_skipNextDebuggerStepOut(false),
+      m_javaScriptPauseScheduled(false),
+      m_steppingFromFramework(false),
+      m_pausingOnNativeEvent(false),
+      m_skippedStepFrameCount(0),
+      m_recursionLevelForStepOut(0),
+      m_recursionLevelForStepFrame(0),
+      m_skipAllPauses(false) {
+  clearBreakDetails();
+}
+
+V8DebuggerAgentImpl::~V8DebuggerAgentImpl() {}
+
+bool V8DebuggerAgentImpl::checkEnabled(ErrorString* errorString) {
+  if (enabled()) return true;
+  *errorString = "Debugger agent is not enabled";
+  return false;
+}
+
+void V8DebuggerAgentImpl::enable() {
+  // m_inspector->addListener may result in reporting all parsed scripts to
+  // the agent so it should already be in enabled state by then.
+  m_enabled = true;
+  m_state->setBoolean(DebuggerAgentState::debuggerEnabled, true);
+  m_debugger->enable();
+
+  std::vector<std::unique_ptr<V8DebuggerScript>> compiledScripts;
+  m_debugger->getCompiledScripts(m_session->contextGroupId(), compiledScripts);
+  for (size_t i = 0; i < compiledScripts.size(); i++)
+    didParseSource(std::move(compiledScripts[i]), true);
+
+  // FIXME(WK44513): breakpoints activated flag should be synchronized between
+  // all front-ends
+  m_debugger->setBreakpointsActivated(true);
+}
+
+bool V8DebuggerAgentImpl::enabled() { return m_enabled; }
+
+void V8DebuggerAgentImpl::enable(ErrorString* errorString) {
+  if (enabled()) return;
+
+  if (!m_inspector->client()->canExecuteScripts(m_session->contextGroupId())) {
+    *errorString = "Script execution is prohibited";
+    return;
+  }
+
+  enable();
+}
+
+void V8DebuggerAgentImpl::disable(ErrorString*) {
+  if (!enabled()) return;
+
+  m_state->setObject(DebuggerAgentState::javaScriptBreakpoints,
+                     protocol::DictionaryValue::create());
+  m_state->setInteger(DebuggerAgentState::pauseOnExceptionsState,
+                      V8Debugger::DontPauseOnExceptions);
+  m_state->setInteger(DebuggerAgentState::asyncCallStackDepth, 0);
+
+  if (!m_pausedContext.IsEmpty()) m_debugger->continueProgram();
+  m_debugger->disable();
+  m_pausedContext.Reset();
+  JavaScriptCallFrames emptyCallFrames;
+  m_pausedCallFrames.swap(emptyCallFrames);
+  m_scripts.clear();
+  m_blackboxedPositions.clear();
+  m_breakpointIdToDebuggerBreakpointIds.clear();
+  m_debugger->setAsyncCallStackDepth(this, 0);
+  m_continueToLocationBreakpointId = String16();
+  clearBreakDetails();
+  m_scheduledDebuggerStep = NoStep;
+  m_skipNextDebuggerStepOut = false;
+  m_javaScriptPauseScheduled = false;
+  m_steppingFromFramework = false;
+  m_pausingOnNativeEvent = false;
+  m_skippedStepFrameCount = 0;
+  m_recursionLevelForStepFrame = 0;
+  m_skipAllPauses = false;
+  m_blackboxPattern = nullptr;
+  m_state->remove(DebuggerAgentState::blackboxPattern);
+  m_enabled = false;
+  m_state->setBoolean(DebuggerAgentState::debuggerEnabled, false);
+}
+
+void V8DebuggerAgentImpl::restore() {
+  DCHECK(!m_enabled);
+  if (!m_state->booleanProperty(DebuggerAgentState::debuggerEnabled, false))
+    return;
+  if (!m_inspector->client()->canExecuteScripts(m_session->contextGroupId()))
+    return;
+
+  enable();
+  ErrorString error;
+
+  int pauseState = V8Debugger::DontPauseOnExceptions;
+  m_state->getInteger(DebuggerAgentState::pauseOnExceptionsState, &pauseState);
+  setPauseOnExceptionsImpl(&error, pauseState);
+  DCHECK(error.isEmpty());
+
+  m_skipAllPauses =
+      m_state->booleanProperty(DebuggerAgentState::skipAllPauses, false);
+
+  int asyncCallStackDepth = 0;
+  m_state->getInteger(DebuggerAgentState::asyncCallStackDepth,
+                      &asyncCallStackDepth);
+  m_debugger->setAsyncCallStackDepth(this, asyncCallStackDepth);
+
+  String16 blackboxPattern;
+  if (m_state->getString(DebuggerAgentState::blackboxPattern,
+                         &blackboxPattern)) {
+    if (!setBlackboxPattern(&error, blackboxPattern)) NOTREACHED();
+  }
+}
+
+void V8DebuggerAgentImpl::setBreakpointsActive(ErrorString* errorString,
+                                               bool active) {
+  if (!checkEnabled(errorString)) return;
+  m_debugger->setBreakpointsActivated(active);
+}
+
+void V8DebuggerAgentImpl::setSkipAllPauses(ErrorString*, bool skip) {
+  m_skipAllPauses = skip;
+  m_state->setBoolean(DebuggerAgentState::skipAllPauses, m_skipAllPauses);
+}
+
+static std::unique_ptr<protocol::DictionaryValue>
+buildObjectForBreakpointCookie(const String16& url, int lineNumber,
+                               int columnNumber, const String16& condition,
+                               bool isRegex) {
+  std::unique_ptr<protocol::DictionaryValue> breakpointObject =
+      protocol::DictionaryValue::create();
+  breakpointObject->setString(DebuggerAgentState::url, url);
+  breakpointObject->setInteger(DebuggerAgentState::lineNumber, lineNumber);
+  breakpointObject->setInteger(DebuggerAgentState::columnNumber, columnNumber);
+  breakpointObject->setString(DebuggerAgentState::condition, condition);
+  breakpointObject->setBoolean(DebuggerAgentState::isRegex, isRegex);
+  return breakpointObject;
+}
+
+static bool matches(V8InspectorImpl* inspector, const String16& url,
+                    const String16& pattern, bool isRegex) {
+  if (isRegex) {
+    V8Regex regex(inspector, pattern, true);
+    return regex.match(url) != -1;
+  }
+  return url == pattern;
+}
+
+void V8DebuggerAgentImpl::setBreakpointByUrl(
+    ErrorString* errorString, int lineNumber,
+    const Maybe<String16>& optionalURL, const Maybe<String16>& optionalURLRegex,
+    const Maybe<int>& optionalColumnNumber,
+    const Maybe<String16>& optionalCondition, String16* outBreakpointId,
+    std::unique_ptr<protocol::Array<protocol::Debugger::Location>>* locations) {
+  *locations = Array<protocol::Debugger::Location>::create();
+  if (optionalURL.isJust() == optionalURLRegex.isJust()) {
+    *errorString = "Either url or urlRegex must be specified.";
+    return;
+  }
+
+  String16 url = optionalURL.isJust() ? optionalURL.fromJust()
+                                      : optionalURLRegex.fromJust();
+  int columnNumber = 0;
+  if (optionalColumnNumber.isJust()) {
+    columnNumber = optionalColumnNumber.fromJust();
+    if (columnNumber < 0) {
+      *errorString = "Incorrect column number";
+      return;
+    }
+  }
+  String16 condition = optionalCondition.fromMaybe("");
+  bool isRegex = optionalURLRegex.isJust();
+
+  String16 breakpointId = (isRegex ? "/" + url + "/" : url) + ":" +
+                          String16::fromInteger(lineNumber) + ":" +
+                          String16::fromInteger(columnNumber);
+  protocol::DictionaryValue* breakpointsCookie =
+      m_state->getObject(DebuggerAgentState::javaScriptBreakpoints);
+  if (!breakpointsCookie) {
+    std::unique_ptr<protocol::DictionaryValue> newValue =
+        protocol::DictionaryValue::create();
+    breakpointsCookie = newValue.get();
+    m_state->setObject(DebuggerAgentState::javaScriptBreakpoints,
+                       std::move(newValue));
+  }
+  if (breakpointsCookie->get(breakpointId)) {
+    *errorString = "Breakpoint at specified location already exists.";
+    return;
+  }
+
+  breakpointsCookie->setObject(
+      breakpointId, buildObjectForBreakpointCookie(
+                        url, lineNumber, columnNumber, condition, isRegex));
+
+  ScriptBreakpoint breakpoint(lineNumber, columnNumber, condition);
+  for (const auto& script : m_scripts) {
+    if (!matches(m_inspector, script.second->sourceURL(), url, isRegex))
+      continue;
+    std::unique_ptr<protocol::Debugger::Location> location = resolveBreakpoint(
+        breakpointId, script.first, breakpoint, UserBreakpointSource);
+    if (location) (*locations)->addItem(std::move(location));
+  }
+
+  *outBreakpointId = breakpointId;
+}
+
+static bool parseLocation(
+    ErrorString* errorString,
+    std::unique_ptr<protocol::Debugger::Location> location, String16* scriptId,
+    int* lineNumber, int* columnNumber) {
+  *scriptId = location->getScriptId();
+  *lineNumber = location->getLineNumber();
+  *columnNumber = location->getColumnNumber(0);
+  return true;
+}
+
+void V8DebuggerAgentImpl::setBreakpoint(
+    ErrorString* errorString,
+    std::unique_ptr<protocol::Debugger::Location> location,
+    const Maybe<String16>& optionalCondition, String16* outBreakpointId,
+    std::unique_ptr<protocol::Debugger::Location>* actualLocation) {
+  String16 scriptId;
+  int lineNumber;
+  int columnNumber;
+
+  if (!parseLocation(errorString, std::move(location), &scriptId, &lineNumber,
+                     &columnNumber))
+    return;
+
+  String16 condition = optionalCondition.fromMaybe("");
+
+  String16 breakpointId = generateBreakpointId(
+      scriptId, lineNumber, columnNumber, UserBreakpointSource);
+  if (m_breakpointIdToDebuggerBreakpointIds.find(breakpointId) !=
+      m_breakpointIdToDebuggerBreakpointIds.end()) {
+    *errorString = "Breakpoint at specified location already exists.";
+    return;
+  }
+  ScriptBreakpoint breakpoint(lineNumber, columnNumber, condition);
+  *actualLocation = resolveBreakpoint(breakpointId, scriptId, breakpoint,
+                                      UserBreakpointSource);
+  if (*actualLocation)
+    *outBreakpointId = breakpointId;
+  else
+    *errorString = "Could not resolve breakpoint";
+}
+
+void V8DebuggerAgentImpl::removeBreakpoint(ErrorString* errorString,
+                                           const String16& breakpointId) {
+  if (!checkEnabled(errorString)) return;
+  protocol::DictionaryValue* breakpointsCookie =
+      m_state->getObject(DebuggerAgentState::javaScriptBreakpoints);
+  if (breakpointsCookie) breakpointsCookie->remove(breakpointId);
+  removeBreakpoint(breakpointId);
+}
+
+void V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
+  DCHECK(enabled());
+  BreakpointIdToDebuggerBreakpointIdsMap::iterator
+      debuggerBreakpointIdsIterator =
+          m_breakpointIdToDebuggerBreakpointIds.find(breakpointId);
+  if (debuggerBreakpointIdsIterator ==
+      m_breakpointIdToDebuggerBreakpointIds.end())
+    return;
+  const std::vector<String16>& ids = debuggerBreakpointIdsIterator->second;
+  for (size_t i = 0; i < ids.size(); ++i) {
+    const String16& debuggerBreakpointId = ids[i];
+
+    m_debugger->removeBreakpoint(debuggerBreakpointId);
+    m_serverBreakpoints.erase(debuggerBreakpointId);
+  }
+  m_breakpointIdToDebuggerBreakpointIds.erase(breakpointId);
+}
+
+void V8DebuggerAgentImpl::continueToLocation(
+    ErrorString* errorString,
+    std::unique_ptr<protocol::Debugger::Location> location) {
+  if (!checkEnabled(errorString)) return;
+  if (!m_continueToLocationBreakpointId.isEmpty()) {
+    m_debugger->removeBreakpoint(m_continueToLocationBreakpointId);
+    m_continueToLocationBreakpointId = "";
+  }
+
+  String16 scriptId;
+  int lineNumber;
+  int columnNumber;
+
+  if (!parseLocation(errorString, std::move(location), &scriptId, &lineNumber,
+                     &columnNumber))
+    return;
+
+  ScriptBreakpoint breakpoint(lineNumber, columnNumber, "");
+  m_continueToLocationBreakpointId = m_debugger->setBreakpoint(
+      scriptId, breakpoint, &lineNumber, &columnNumber);
+  resume(errorString);
+}
+
+bool V8DebuggerAgentImpl::isCurrentCallStackEmptyOrBlackboxed() {
+  DCHECK(enabled());
+  JavaScriptCallFrames callFrames = m_debugger->currentCallFrames();
+  for (size_t index = 0; index < callFrames.size(); ++index) {
+    if (!isCallFrameWithUnknownScriptOrBlackboxed(callFrames[index].get()))
+      return false;
+  }
+  return true;
+}
+
+bool V8DebuggerAgentImpl::isTopPausedCallFrameBlackboxed() {
+  DCHECK(enabled());
+  JavaScriptCallFrame* frame =
+      m_pausedCallFrames.size() ? m_pausedCallFrames[0].get() : nullptr;
+  return isCallFrameWithUnknownScriptOrBlackboxed(frame);
+}
+
+bool V8DebuggerAgentImpl::isCallFrameWithUnknownScriptOrBlackboxed(
+    JavaScriptCallFrame* frame) {
+  if (!frame) return true;
+  ScriptsMap::iterator it =
+      m_scripts.find(String16::fromInteger(frame->sourceID()));
+  if (it == m_scripts.end()) {
+    // Unknown scripts are blackboxed.
+    return true;
+  }
+  if (m_blackboxPattern) {
+    const String16& scriptSourceURL = it->second->sourceURL();
+    if (!scriptSourceURL.isEmpty() &&
+        m_blackboxPattern->match(scriptSourceURL) != -1)
+      return true;
+  }
+  auto itBlackboxedPositions =
+      m_blackboxedPositions.find(String16::fromInteger(frame->sourceID()));
+  if (itBlackboxedPositions == m_blackboxedPositions.end()) return false;
+
+  const std::vector<std::pair<int, int>>& ranges =
+      itBlackboxedPositions->second;
+  auto itRange = std::lower_bound(
+      ranges.begin(), ranges.end(),
+      std::make_pair(frame->line(), frame->column()), positionComparator);
+  // Ranges array contains positions in script where blackbox state is changed.
+  // [(0,0) ... ranges[0]) isn't blackboxed, [ranges[0] ... ranges[1]) is
+  // blackboxed...
+  return std::distance(ranges.begin(), itRange) % 2;
+}
+
+V8DebuggerAgentImpl::SkipPauseRequest
+V8DebuggerAgentImpl::shouldSkipExceptionPause(
+    JavaScriptCallFrame* topCallFrame) {
+  if (m_steppingFromFramework) return RequestNoSkip;
+  if (isCallFrameWithUnknownScriptOrBlackboxed(topCallFrame))
+    return RequestContinue;
+  return RequestNoSkip;
+}
+
+V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::shouldSkipStepPause(
+    JavaScriptCallFrame* topCallFrame) {
+  if (m_steppingFromFramework) return RequestNoSkip;
+
+  if (m_skipNextDebuggerStepOut) {
+    m_skipNextDebuggerStepOut = false;
+    if (m_scheduledDebuggerStep == StepOut) return RequestStepOut;
+  }
+
+  if (!isCallFrameWithUnknownScriptOrBlackboxed(topCallFrame))
+    return RequestNoSkip;
+
+  if (m_skippedStepFrameCount >= maxSkipStepFrameCount) return RequestStepOut;
+
+  if (!m_skippedStepFrameCount) m_recursionLevelForStepFrame = 1;
+
+  ++m_skippedStepFrameCount;
+  return RequestStepFrame;
+}
+
+std::unique_ptr<protocol::Debugger::Location>
+V8DebuggerAgentImpl::resolveBreakpoint(const String16& breakpointId,
+                                       const String16& scriptId,
+                                       const ScriptBreakpoint& breakpoint,
+                                       BreakpointSource source) {
+  DCHECK(enabled());
+  // FIXME: remove these checks once crbug.com/520702 is resolved.
+  CHECK(!breakpointId.isEmpty());
+  CHECK(!scriptId.isEmpty());
+  ScriptsMap::iterator scriptIterator = m_scripts.find(scriptId);
+  if (scriptIterator == m_scripts.end()) return nullptr;
+  if (breakpoint.lineNumber < scriptIterator->second->startLine() ||
+      scriptIterator->second->endLine() < breakpoint.lineNumber)
+    return nullptr;
+
+  int actualLineNumber;
+  int actualColumnNumber;
+  String16 debuggerBreakpointId = m_debugger->setBreakpoint(
+      scriptId, breakpoint, &actualLineNumber, &actualColumnNumber);
+  if (debuggerBreakpointId.isEmpty()) return nullptr;
+
+  m_serverBreakpoints[debuggerBreakpointId] =
+      std::make_pair(breakpointId, source);
+  CHECK(!breakpointId.isEmpty());
+
+  m_breakpointIdToDebuggerBreakpointIds[breakpointId].push_back(
+      debuggerBreakpointId);
+  return buildProtocolLocation(scriptId, actualLineNumber, actualColumnNumber);
+}
+
+void V8DebuggerAgentImpl::searchInContent(
+    ErrorString* error, const String16& scriptId, const String16& query,
+    const Maybe<bool>& optionalCaseSensitive,
+    const Maybe<bool>& optionalIsRegex,
+    std::unique_ptr<Array<protocol::Debugger::SearchMatch>>* results) {
+  v8::HandleScope handles(m_isolate);
+  ScriptsMap::iterator it = m_scripts.find(scriptId);
+  if (it == m_scripts.end()) {
+    *error = String16("No script for id: " + scriptId);
+    return;
+  }
+
+  std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> matches =
+      searchInTextByLinesImpl(m_session,
+                              toProtocolString(it->second->source(m_isolate)),
+                              query, optionalCaseSensitive.fromMaybe(false),
+                              optionalIsRegex.fromMaybe(false));
+  *results = protocol::Array<protocol::Debugger::SearchMatch>::create();
+  for (size_t i = 0; i < matches.size(); ++i)
+    (*results)->addItem(std::move(matches[i]));
+}
+
+void V8DebuggerAgentImpl::setScriptSource(
+    ErrorString* errorString, const String16& scriptId,
+    const String16& newContent, const Maybe<bool>& dryRun,
+    Maybe<protocol::Array<protocol::Debugger::CallFrame>>* newCallFrames,
+    Maybe<bool>* stackChanged, Maybe<StackTrace>* asyncStackTrace,
+    Maybe<protocol::Runtime::ExceptionDetails>* optOutCompileError) {
+  if (!checkEnabled(errorString)) return;
+
+  v8::HandleScope handles(m_isolate);
+  v8::Local<v8::String> newSource = toV8String(m_isolate, newContent);
+  if (!m_debugger->setScriptSource(scriptId, newSource, dryRun.fromMaybe(false),
+                                   errorString, optOutCompileError,
+                                   &m_pausedCallFrames, stackChanged))
+    return;
+
+  ScriptsMap::iterator it = m_scripts.find(scriptId);
+  if (it != m_scripts.end()) it->second->setSource(m_isolate, newSource);
+
+  std::unique_ptr<Array<CallFrame>> callFrames = currentCallFrames(errorString);
+  if (!callFrames) return;
+  *newCallFrames = std::move(callFrames);
+  *asyncStackTrace = currentAsyncStackTrace();
+}
+
+void V8DebuggerAgentImpl::restartFrame(
+    ErrorString* errorString, const String16& callFrameId,
+    std::unique_ptr<Array<CallFrame>>* newCallFrames,
+    Maybe<StackTrace>* asyncStackTrace) {
+  if (!assertPaused(errorString)) return;
+  InjectedScript::CallFrameScope scope(
+      errorString, m_inspector, m_session->contextGroupId(), callFrameId);
+  if (!scope.initialize()) return;
+  if (scope.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 (!m_pausedCallFrames[scope.frameOrdinal()]->restart().ToLocal(
+          &resultValue) ||
+      scope.tryCatch().HasCaught() ||
+      !resultValue->ToBoolean(scope.context()).ToLocal(&result) ||
+      !result->Value()) {
+    *errorString = "Internal error";
+    return;
+  }
+  JavaScriptCallFrames frames = m_debugger->currentCallFrames();
+  m_pausedCallFrames.swap(frames);
+
+  *newCallFrames = currentCallFrames(errorString);
+  if (!*newCallFrames) return;
+  *asyncStackTrace = currentAsyncStackTrace();
+}
+
+void V8DebuggerAgentImpl::getScriptSource(ErrorString* error,
+                                          const String16& scriptId,
+                                          String16* scriptSource) {
+  if (!checkEnabled(error)) return;
+  ScriptsMap::iterator it = m_scripts.find(scriptId);
+  if (it == m_scripts.end()) {
+    *error = "No script for id: " + scriptId;
+    return;
+  }
+  v8::HandleScope handles(m_isolate);
+  *scriptSource = toProtocolString(it->second->source(m_isolate));
+}
+
+void V8DebuggerAgentImpl::schedulePauseOnNextStatement(
+    const String16& breakReason,
+    std::unique_ptr<protocol::DictionaryValue> data) {
+  if (!enabled() || m_scheduledDebuggerStep == StepInto ||
+      m_javaScriptPauseScheduled || m_debugger->isPaused() ||
+      !m_debugger->breakpointsActivated())
+    return;
+  m_breakReason = breakReason;
+  m_breakAuxData = std::move(data);
+  m_pausingOnNativeEvent = true;
+  m_skipNextDebuggerStepOut = false;
+  m_debugger->setPauseOnNextStatement(true);
+}
+
+void V8DebuggerAgentImpl::schedulePauseOnNextStatementIfSteppingInto() {
+  DCHECK(enabled());
+  if (m_scheduledDebuggerStep != StepInto || m_javaScriptPauseScheduled ||
+      m_debugger->isPaused())
+    return;
+  clearBreakDetails();
+  m_pausingOnNativeEvent = false;
+  m_skippedStepFrameCount = 0;
+  m_recursionLevelForStepFrame = 0;
+  m_debugger->setPauseOnNextStatement(true);
+}
+
+void V8DebuggerAgentImpl::cancelPauseOnNextStatement() {
+  if (m_javaScriptPauseScheduled || m_debugger->isPaused()) return;
+  clearBreakDetails();
+  m_pausingOnNativeEvent = false;
+  m_debugger->setPauseOnNextStatement(false);
+}
+
+void V8DebuggerAgentImpl::pause(ErrorString* errorString) {
+  if (!checkEnabled(errorString)) return;
+  if (m_javaScriptPauseScheduled || m_debugger->isPaused()) return;
+  clearBreakDetails();
+  m_javaScriptPauseScheduled = true;
+  m_scheduledDebuggerStep = NoStep;
+  m_skippedStepFrameCount = 0;
+  m_steppingFromFramework = false;
+  m_debugger->setPauseOnNextStatement(true);
+}
+
+void V8DebuggerAgentImpl::resume(ErrorString* errorString) {
+  if (!assertPaused(errorString)) return;
+  m_scheduledDebuggerStep = NoStep;
+  m_steppingFromFramework = false;
+  m_session->releaseObjectGroup(backtraceObjectGroup);
+  m_debugger->continueProgram();
+}
+
+void V8DebuggerAgentImpl::stepOver(ErrorString* errorString) {
+  if (!assertPaused(errorString)) return;
+  // StepOver at function return point should fallback to StepInto.
+  JavaScriptCallFrame* frame =
+      !m_pausedCallFrames.empty() ? m_pausedCallFrames[0].get() : nullptr;
+  if (frame && frame->isAtReturn()) {
+    stepInto(errorString);
+    return;
+  }
+  m_scheduledDebuggerStep = StepOver;
+  m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
+  m_session->releaseObjectGroup(backtraceObjectGroup);
+  m_debugger->stepOverStatement();
+}
+
+void V8DebuggerAgentImpl::stepInto(ErrorString* errorString) {
+  if (!assertPaused(errorString)) return;
+  m_scheduledDebuggerStep = StepInto;
+  m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
+  m_session->releaseObjectGroup(backtraceObjectGroup);
+  m_debugger->stepIntoStatement();
+}
+
+void V8DebuggerAgentImpl::stepOut(ErrorString* errorString) {
+  if (!assertPaused(errorString)) return;
+  m_scheduledDebuggerStep = StepOut;
+  m_skipNextDebuggerStepOut = false;
+  m_recursionLevelForStepOut = 1;
+  m_steppingFromFramework = isTopPausedCallFrameBlackboxed();
+  m_session->releaseObjectGroup(backtraceObjectGroup);
+  m_debugger->stepOutOfFunction();
+}
+
+void V8DebuggerAgentImpl::setPauseOnExceptions(
+    ErrorString* errorString, const String16& stringPauseState) {
+  if (!checkEnabled(errorString)) return;
+  V8Debugger::PauseOnExceptionsState pauseState;
+  if (stringPauseState == "none") {
+    pauseState = V8Debugger::DontPauseOnExceptions;
+  } else if (stringPauseState == "all") {
+    pauseState = V8Debugger::PauseOnAllExceptions;
+  } else if (stringPauseState == "uncaught") {
+    pauseState = V8Debugger::PauseOnUncaughtExceptions;
+  } else {
+    *errorString = "Unknown pause on exceptions mode: " + stringPauseState;
+    return;
+  }
+  setPauseOnExceptionsImpl(errorString, pauseState);
+}
+
+void V8DebuggerAgentImpl::setPauseOnExceptionsImpl(ErrorString* errorString,
+                                                   int pauseState) {
+  m_debugger->setPauseOnExceptionsState(
+      static_cast<V8Debugger::PauseOnExceptionsState>(pauseState));
+  if (m_debugger->getPauseOnExceptionsState() != pauseState)
+    *errorString = "Internal error. Could not change pause on exceptions state";
+  else
+    m_state->setInteger(DebuggerAgentState::pauseOnExceptionsState, pauseState);
+}
+
+void V8DebuggerAgentImpl::evaluateOnCallFrame(
+    ErrorString* errorString, const String16& callFrameId,
+    const String16& expression, const Maybe<String16>& objectGroup,
+    const Maybe<bool>& includeCommandLineAPI, const Maybe<bool>& silent,
+    const Maybe<bool>& returnByValue, const Maybe<bool>& generatePreview,
+    std::unique_ptr<RemoteObject>* result,
+    Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
+  if (!assertPaused(errorString)) return;
+  InjectedScript::CallFrameScope scope(
+      errorString, m_inspector, m_session->contextGroupId(), callFrameId);
+  if (!scope.initialize()) return;
+  if (scope.frameOrdinal() >= m_pausedCallFrames.size()) {
+    *errorString = "Could not find call frame with given id";
+    return;
+  }
+
+  if (includeCommandLineAPI.fromMaybe(false) && !scope.installCommandLineAPI())
+    return;
+  if (silent.fromMaybe(false)) scope.ignoreExceptionsAndMuteConsole();
+
+  v8::MaybeLocal<v8::Value> maybeResultValue =
+      m_pausedCallFrames[scope.frameOrdinal()]->evaluate(
+          toV8String(m_isolate, expression));
+
+  // Re-initialize after running client's code, as it could have destroyed
+  // context or session.
+  if (!scope.initialize()) return;
+  scope.injectedScript()->wrapEvaluateResult(
+      errorString, maybeResultValue, scope.tryCatch(),
+      objectGroup.fromMaybe(""), returnByValue.fromMaybe(false),
+      generatePreview.fromMaybe(false), result, exceptionDetails);
+}
+
+void V8DebuggerAgentImpl::setVariableValue(
+    ErrorString* errorString, int scopeNumber, const String16& variableName,
+    std::unique_ptr<protocol::Runtime::CallArgument> newValueArgument,
+    const String16& callFrameId) {
+  if (!checkEnabled(errorString)) return;
+  if (!assertPaused(errorString)) return;
+  InjectedScript::CallFrameScope scope(
+      errorString, m_inspector, m_session->contextGroupId(), callFrameId);
+  if (!scope.initialize()) return;
+
+  v8::Local<v8::Value> newValue;
+  if (!scope.injectedScript()
+           ->resolveCallArgument(errorString, newValueArgument.get())
+           .ToLocal(&newValue))
+    return;
+
+  if (scope.frameOrdinal() >= m_pausedCallFrames.size()) {
+    *errorString = "Could not find call frame with given id";
+    return;
+  }
+  v8::MaybeLocal<v8::Value> result =
+      m_pausedCallFrames[scope.frameOrdinal()]->setVariableValue(
+          scopeNumber, toV8String(m_isolate, variableName), newValue);
+  if (scope.tryCatch().HasCaught() || result.IsEmpty()) {
+    *errorString = "Internal error";
+    return;
+  }
+}
+
+void V8DebuggerAgentImpl::setAsyncCallStackDepth(ErrorString* errorString,
+                                                 int depth) {
+  if (!checkEnabled(errorString)) return;
+  m_state->setInteger(DebuggerAgentState::asyncCallStackDepth, depth);
+  m_debugger->setAsyncCallStackDepth(this, depth);
+}
+
+void V8DebuggerAgentImpl::setBlackboxPatterns(
+    ErrorString* errorString,
+    std::unique_ptr<protocol::Array<String16>> patterns) {
+  if (!patterns->length()) {
+    m_blackboxPattern = nullptr;
+    m_state->remove(DebuggerAgentState::blackboxPattern);
+    return;
+  }
+
+  String16Builder patternBuilder;
+  patternBuilder.append('(');
+  for (size_t i = 0; i < patterns->length() - 1; ++i) {
+    patternBuilder.append(patterns->get(i));
+    patternBuilder.append("|");
+  }
+  patternBuilder.append(patterns->get(patterns->length() - 1));
+  patternBuilder.append(')');
+  String16 pattern = patternBuilder.toString();
+  if (!setBlackboxPattern(errorString, pattern)) return;
+  m_state->setString(DebuggerAgentState::blackboxPattern, pattern);
+}
+
+bool V8DebuggerAgentImpl::setBlackboxPattern(ErrorString* errorString,
+                                             const String16& pattern) {
+  std::unique_ptr<V8Regex> regex(new V8Regex(
+      m_inspector, pattern, true /** caseSensitive */, false /** multiline */));
+  if (!regex->isValid()) {
+    *errorString = "Pattern parser error: " + regex->errorMessage();
+    return false;
+  }
+  m_blackboxPattern = std::move(regex);
+  return true;
+}
+
+void V8DebuggerAgentImpl::setBlackboxedRanges(
+    ErrorString* error, const String16& scriptId,
+    std::unique_ptr<protocol::Array<protocol::Debugger::ScriptPosition>>
+        inPositions) {
+  if (m_scripts.find(scriptId) == m_scripts.end()) {
+    *error = "No script with passed id.";
+    return;
+  }
+
+  if (!inPositions->length()) {
+    m_blackboxedPositions.erase(scriptId);
+    return;
+  }
+
+  std::vector<std::pair<int, int>> positions;
+  positions.reserve(inPositions->length());
+  for (size_t i = 0; i < inPositions->length(); ++i) {
+    protocol::Debugger::ScriptPosition* position = inPositions->get(i);
+    if (position->getLineNumber() < 0) {
+      *error = "Position missing 'line' or 'line' < 0.";
+      return;
+    }
+    if (position->getColumnNumber() < 0) {
+      *error = "Position missing 'column' or 'column' < 0.";
+      return;
+    }
+    positions.push_back(
+        std::make_pair(position->getLineNumber(), position->getColumnNumber()));
+  }
+
+  for (size_t i = 1; i < positions.size(); ++i) {
+    if (positions[i - 1].first < positions[i].first) continue;
+    if (positions[i - 1].first == positions[i].first &&
+        positions[i - 1].second < positions[i].second)
+      continue;
+    *error =
+        "Input positions array is not sorted or contains duplicate values.";
+    return;
+  }
+
+  m_blackboxedPositions[scriptId] = positions;
+}
+
+void V8DebuggerAgentImpl::willExecuteScript(int scriptId) {
+  changeJavaScriptRecursionLevel(+1);
+  // Fast return.
+  if (m_scheduledDebuggerStep != StepInto) return;
+  schedulePauseOnNextStatementIfSteppingInto();
+}
+
+void V8DebuggerAgentImpl::didExecuteScript() {
+  changeJavaScriptRecursionLevel(-1);
+}
+
+void V8DebuggerAgentImpl::changeJavaScriptRecursionLevel(int step) {
+  if (m_javaScriptPauseScheduled && !m_skipAllPauses &&
+      !m_debugger->isPaused()) {
+    // Do not ever loose user's pause request until we have actually paused.
+    m_debugger->setPauseOnNextStatement(true);
+  }
+  if (m_scheduledDebuggerStep == StepOut) {
+    m_recursionLevelForStepOut += step;
+    if (!m_recursionLevelForStepOut) {
+      // When StepOut crosses a task boundary (i.e. js -> c++) from where it was
+      // requested,
+      // switch stepping to step into a next JS task, as if we exited to a
+      // blackboxed framework.
+      m_scheduledDebuggerStep = StepInto;
+      m_skipNextDebuggerStepOut = false;
+    }
+  }
+  if (m_recursionLevelForStepFrame) {
+    m_recursionLevelForStepFrame += step;
+    if (!m_recursionLevelForStepFrame) {
+      // We have walked through a blackboxed framework and got back to where we
+      // started.
+      // If there was no stepping scheduled, we should cancel the stepping
+      // explicitly,
+      // since there may be a scheduled StepFrame left.
+      // Otherwise, if we were stepping in/over, the StepFrame will stop at the
+      // right location,
+      // whereas if we were stepping out, we should continue doing so after
+      // debugger pauses
+      // from the old StepFrame.
+      m_skippedStepFrameCount = 0;
+      if (m_scheduledDebuggerStep == NoStep)
+        m_debugger->clearStepping();
+      else if (m_scheduledDebuggerStep == StepOut)
+        m_skipNextDebuggerStepOut = true;
+    }
+  }
+}
+
+std::unique_ptr<Array<CallFrame>> V8DebuggerAgentImpl::currentCallFrames(
+    ErrorString* errorString) {
+  if (m_pausedContext.IsEmpty() || !m_pausedCallFrames.size())
+    return Array<CallFrame>::create();
+  ErrorString ignored;
+  v8::HandleScope handles(m_isolate);
+  v8::Local<v8::Context> debuggerContext =
+      v8::Debug::GetDebugContext(m_isolate);
+  v8::Context::Scope contextScope(debuggerContext);
+
+  v8::Local<v8::Array> objects = v8::Array::New(m_isolate);
+
+  for (size_t frameOrdinal = 0; frameOrdinal < m_pausedCallFrames.size();
+       ++frameOrdinal) {
+    const std::unique_ptr<JavaScriptCallFrame>& currentCallFrame =
+        m_pausedCallFrames[frameOrdinal];
+
+    v8::Local<v8::Object> details = currentCallFrame->details();
+    if (hasInternalError(errorString, details.IsEmpty()))
+      return Array<CallFrame>::create();
+
+    int contextId = currentCallFrame->contextId();
+    InjectedScript* injectedScript =
+        contextId ? m_session->findInjectedScript(&ignored, contextId)
+                  : nullptr;
+
+    String16 callFrameId =
+        RemoteCallFrameId::serialize(contextId, frameOrdinal);
+    if (hasInternalError(
+            errorString,
+            !details
+                 ->Set(debuggerContext,
+                       toV8StringInternalized(m_isolate, "callFrameId"),
+                       toV8String(m_isolate, callFrameId))
+                 .FromMaybe(false)))
+      return Array<CallFrame>::create();
+
+    if (injectedScript) {
+      v8::Local<v8::Value> scopeChain;
+      if (hasInternalError(
+              errorString,
+              !details->Get(debuggerContext,
+                            toV8StringInternalized(m_isolate, "scopeChain"))
+                      .ToLocal(&scopeChain) ||
+                  !scopeChain->IsArray()))
+        return Array<CallFrame>::create();
+      v8::Local<v8::Array> scopeChainArray = scopeChain.As<v8::Array>();
+      if (!injectedScript->wrapPropertyInArray(
+              errorString, scopeChainArray,
+              toV8StringInternalized(m_isolate, "object"),
+              backtraceObjectGroup))
+        return Array<CallFrame>::create();
+      if (!injectedScript->wrapObjectProperty(
+              errorString, details, toV8StringInternalized(m_isolate, "this"),
+              backtraceObjectGroup))
+        return Array<CallFrame>::create();
+      if (details
+              ->Has(debuggerContext,
+                    toV8StringInternalized(m_isolate, "returnValue"))
+              .FromMaybe(false)) {
+        if (!injectedScript->wrapObjectProperty(
+                errorString, details,
+                toV8StringInternalized(m_isolate, "returnValue"),
+                backtraceObjectGroup))
+          return Array<CallFrame>::create();
+      }
+    } else {
+      if (hasInternalError(errorString, !details
+                                             ->Set(debuggerContext,
+                                                   toV8StringInternalized(
+                                                       m_isolate, "scopeChain"),
+                                                   v8::Array::New(m_isolate, 0))
+                                             .FromMaybe(false)))
+        return Array<CallFrame>::create();
+      v8::Local<v8::Object> remoteObject = v8::Object::New(m_isolate);
+      if (hasInternalError(
+              errorString,
+              !remoteObject
+                   ->Set(debuggerContext,
+                         toV8StringInternalized(m_isolate, "type"),
+                         toV8StringInternalized(m_isolate, "undefined"))
+                   .FromMaybe(false)))
+        return Array<CallFrame>::create();
+      if (hasInternalError(errorString,
+                           !details
+                                ->Set(debuggerContext,
+                                      toV8StringInternalized(m_isolate, "this"),
+                                      remoteObject)
+                                .FromMaybe(false)))
+        return Array<CallFrame>::create();
+      if (hasInternalError(
+              errorString,
+              !details
+                   ->Delete(debuggerContext,
+                            toV8StringInternalized(m_isolate, "returnValue"))
+                   .FromMaybe(false)))
+        return Array<CallFrame>::create();
+    }
+
+    if (hasInternalError(errorString,
+                         !objects->Set(debuggerContext, frameOrdinal, details)
+                              .FromMaybe(false)))
+      return Array<CallFrame>::create();
+  }
+
+  protocol::ErrorSupport errorSupport;
+  std::unique_ptr<Array<CallFrame>> callFrames = Array<CallFrame>::parse(
+      toProtocolValue(debuggerContext, objects).get(), &errorSupport);
+  if (hasInternalError(errorString, !callFrames))
+    return Array<CallFrame>::create();
+  return callFrames;
+}
+
+std::unique_ptr<StackTrace> V8DebuggerAgentImpl::currentAsyncStackTrace() {
+  if (m_pausedContext.IsEmpty()) return nullptr;
+  V8StackTraceImpl* stackTrace = m_debugger->currentAsyncCallChain();
+  return stackTrace ? stackTrace->buildInspectorObjectForTail(m_debugger)
+                    : nullptr;
+}
+
+void V8DebuggerAgentImpl::didParseSource(
+    std::unique_ptr<V8DebuggerScript> script, bool success) {
+  v8::HandleScope handles(m_isolate);
+  String16 scriptSource = toProtocolString(script->source(m_isolate));
+  if (!success) script->setSourceURL(findSourceURL(scriptSource, false));
+  if (!success)
+    script->setSourceMappingURL(findSourceMapURL(scriptSource, false));
+
+  std::unique_ptr<protocol::DictionaryValue> executionContextAuxData;
+  if (!script->executionContextAuxData().isEmpty())
+    executionContextAuxData = protocol::DictionaryValue::cast(
+        protocol::parseJSON(script->executionContextAuxData()));
+  bool isLiveEdit = script->isLiveEdit();
+  bool hasSourceURL = script->hasSourceURL();
+  String16 scriptId = script->scriptId();
+  String16 scriptURL = script->sourceURL();
+
+  const Maybe<String16>& sourceMapURLParam = script->sourceMappingURL();
+  const Maybe<protocol::DictionaryValue>& executionContextAuxDataParam(
+      std::move(executionContextAuxData));
+  const bool* isLiveEditParam = isLiveEdit ? &isLiveEdit : nullptr;
+  const bool* hasSourceURLParam = hasSourceURL ? &hasSourceURL : nullptr;
+  if (success)
+    m_frontend.scriptParsed(
+        scriptId, scriptURL, script->startLine(), script->startColumn(),
+        script->endLine(), script->endColumn(), script->executionContextId(),
+        script->hash(), executionContextAuxDataParam, isLiveEditParam,
+        sourceMapURLParam, hasSourceURLParam);
+  else
+    m_frontend.scriptFailedToParse(
+        scriptId, scriptURL, script->startLine(), script->startColumn(),
+        script->endLine(), script->endColumn(), script->executionContextId(),
+        script->hash(), executionContextAuxDataParam, sourceMapURLParam,
+        hasSourceURLParam);
+
+  m_scripts[scriptId] = std::move(script);
+
+  if (scriptURL.isEmpty() || !success) return;
+
+  protocol::DictionaryValue* breakpointsCookie =
+      m_state->getObject(DebuggerAgentState::javaScriptBreakpoints);
+  if (!breakpointsCookie) return;
+
+  for (size_t i = 0; i < breakpointsCookie->size(); ++i) {
+    auto cookie = breakpointsCookie->at(i);
+    protocol::DictionaryValue* breakpointObject =
+        protocol::DictionaryValue::cast(cookie.second);
+    bool isRegex;
+    breakpointObject->getBoolean(DebuggerAgentState::isRegex, &isRegex);
+    String16 url;
+    breakpointObject->getString(DebuggerAgentState::url, &url);
+    if (!matches(m_inspector, scriptURL, url, isRegex)) continue;
+    ScriptBreakpoint breakpoint;
+    breakpointObject->getInteger(DebuggerAgentState::lineNumber,
+                                 &breakpoint.lineNumber);
+    breakpointObject->getInteger(DebuggerAgentState::columnNumber,
+                                 &breakpoint.columnNumber);
+    breakpointObject->getString(DebuggerAgentState::condition,
+                                &breakpoint.condition);
+    std::unique_ptr<protocol::Debugger::Location> location = resolveBreakpoint(
+        cookie.first, scriptId, breakpoint, UserBreakpointSource);
+    if (location)
+      m_frontend.breakpointResolved(cookie.first, std::move(location));
+  }
+}
+
+V8DebuggerAgentImpl::SkipPauseRequest V8DebuggerAgentImpl::didPause(
+    v8::Local<v8::Context> context, v8::Local<v8::Value> exception,
+    const std::vector<String16>& hitBreakpoints, bool isPromiseRejection) {
+  JavaScriptCallFrames callFrames = m_debugger->currentCallFrames(1);
+  JavaScriptCallFrame* topCallFrame =
+      !callFrames.empty() ? callFrames.begin()->get() : nullptr;
+
+  V8DebuggerAgentImpl::SkipPauseRequest result;
+  if (m_skipAllPauses)
+    result = RequestContinue;
+  else if (!hitBreakpoints.empty())
+    result = RequestNoSkip;  // Don't skip explicit breakpoints even if set in
+                             // frameworks.
+  else if (!exception.IsEmpty())
+    result = shouldSkipExceptionPause(topCallFrame);
+  else if (m_scheduledDebuggerStep != NoStep || m_javaScriptPauseScheduled ||
+           m_pausingOnNativeEvent)
+    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 (!topCallFrame) return RequestContinue;
+
+  DCHECK(m_pausedContext.IsEmpty());
+  JavaScriptCallFrames frames = m_debugger->currentCallFrames();
+  m_pausedCallFrames.swap(frames);
+  m_pausedContext.Reset(m_isolate, context);
+  v8::HandleScope handles(m_isolate);
+
+  if (!exception.IsEmpty()) {
+    ErrorString ignored;
+    InjectedScript* injectedScript =
+        m_session->findInjectedScript(&ignored, V8Debugger::contextId(context));
+    if (injectedScript) {
+      m_breakReason =
+          isPromiseRejection
+              ? protocol::Debugger::Paused::ReasonEnum::PromiseRejection
+              : protocol::Debugger::Paused::ReasonEnum::Exception;
+      ErrorString errorString;
+      auto obj = injectedScript->wrapObject(&errorString, exception,
+                                            backtraceObjectGroup);
+      m_breakAuxData = obj ? obj->serialize() : nullptr;
+      // m_breakAuxData might be null after this.
+    }
+  }
+
+  std::unique_ptr<Array<String16>> hitBreakpointIds = Array<String16>::create();
+
+  for (const auto& point : hitBreakpoints) {
+    DebugServerBreakpointToBreakpointIdAndSourceMap::iterator
+        breakpointIterator = m_serverBreakpoints.find(point);
+    if (breakpointIterator != m_serverBreakpoints.end()) {
+      const String16& localId = breakpointIterator->second.first;
+      hitBreakpointIds->addItem(localId);
+
+      BreakpointSource source = breakpointIterator->second.second;
+      if (m_breakReason == protocol::Debugger::Paused::ReasonEnum::Other &&
+          source == DebugCommandBreakpointSource)
+        m_breakReason = protocol::Debugger::Paused::ReasonEnum::DebugCommand;
+    }
+  }
+
+  ErrorString errorString;
+  m_frontend.paused(currentCallFrames(&errorString), m_breakReason,
+                    std::move(m_breakAuxData), std::move(hitBreakpointIds),
+                    currentAsyncStackTrace());
+  m_scheduledDebuggerStep = NoStep;
+  m_javaScriptPauseScheduled = false;
+  m_steppingFromFramework = false;
+  m_pausingOnNativeEvent = false;
+  m_skippedStepFrameCount = 0;
+  m_recursionLevelForStepFrame = 0;
+
+  if (!m_continueToLocationBreakpointId.isEmpty()) {
+    m_debugger->removeBreakpoint(m_continueToLocationBreakpointId);
+    m_continueToLocationBreakpointId = "";
+  }
+  return result;
+}
+
+void V8DebuggerAgentImpl::didContinue() {
+  m_pausedContext.Reset();
+  JavaScriptCallFrames emptyCallFrames;
+  m_pausedCallFrames.swap(emptyCallFrames);
+  clearBreakDetails();
+  m_frontend.resumed();
+}
+
+void V8DebuggerAgentImpl::breakProgram(
+    const String16& breakReason,
+    std::unique_ptr<protocol::DictionaryValue> data) {
+  if (!enabled() || m_skipAllPauses || !m_pausedContext.IsEmpty() ||
+      isCurrentCallStackEmptyOrBlackboxed() ||
+      !m_debugger->breakpointsActivated())
+    return;
+  m_breakReason = breakReason;
+  m_breakAuxData = std::move(data);
+  m_scheduledDebuggerStep = NoStep;
+  m_steppingFromFramework = false;
+  m_pausingOnNativeEvent = false;
+  m_debugger->breakProgram();
+}
+
+void V8DebuggerAgentImpl::breakProgramOnException(
+    const String16& breakReason,
+    std::unique_ptr<protocol::DictionaryValue> data) {
+  if (!enabled() ||
+      m_debugger->getPauseOnExceptionsState() ==
+          V8Debugger::DontPauseOnExceptions)
+    return;
+  breakProgram(breakReason, std::move(data));
+}
+
+bool V8DebuggerAgentImpl::assertPaused(ErrorString* errorString) {
+  if (m_pausedContext.IsEmpty()) {
+    *errorString = "Can only perform operation while paused.";
+    return false;
+  }
+  return true;
+}
+
+void V8DebuggerAgentImpl::clearBreakDetails() {
+  m_breakReason = protocol::Debugger::Paused::ReasonEnum::Other;
+  m_breakAuxData = nullptr;
+}
+
+void V8DebuggerAgentImpl::setBreakpointAt(const String16& scriptId,
+                                          int lineNumber, int columnNumber,
+                                          BreakpointSource source,
+                                          const String16& condition) {
+  String16 breakpointId =
+      generateBreakpointId(scriptId, lineNumber, columnNumber, source);
+  ScriptBreakpoint breakpoint(lineNumber, columnNumber, condition);
+  resolveBreakpoint(breakpointId, scriptId, breakpoint, source);
+}
+
+void V8DebuggerAgentImpl::removeBreakpointAt(const String16& scriptId,
+                                             int lineNumber, int columnNumber,
+                                             BreakpointSource source) {
+  removeBreakpoint(
+      generateBreakpointId(scriptId, lineNumber, columnNumber, source));
+}
+
+void V8DebuggerAgentImpl::reset() {
+  if (!enabled()) return;
+  m_scheduledDebuggerStep = NoStep;
+  m_scripts.clear();
+  m_blackboxedPositions.clear();
+  m_breakpointIdToDebuggerBreakpointIds.clear();
+}
+
+}  // namespace v8_inspector