Add m-esr52 at 52.6.0

1 files changed, 706 insertions, 0 deletions

diff --git a/gfx/2d/Logging.h b/gfx/2d/Logging.h
new file mode 100644
index 000000000..e6be2a7e8
--- /dev/null
+++ b/gfx/2d/Logging.h
@@ -0,0 +1,706 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_LOGGING_H_
+#define MOZILLA_GFX_LOGGING_H_
+
+#include <string>
+#include <sstream>
+#include <stdio.h>
+#include <vector>
+
+#ifdef MOZ_LOGGING
+#include "mozilla/Logging.h"
+#endif
+#include "mozilla/Tuple.h"
+
+#if defined(MOZ_WIDGET_ANDROID)
+#include "nsDebug.h"
+#endif
+#include "Point.h"
+#include "BaseRect.h"
+#include "Matrix.h"
+#include "LoggingConstants.h"
+
+#if defined(MOZ_LOGGING)
+extern GFX2D_API mozilla::LogModule* GetGFX2DLog();
+#endif
+
+namespace mozilla {
+namespace gfx {
+
+#if defined(MOZ_LOGGING)
+inline mozilla::LogLevel PRLogLevelForLevel(int aLevel) {
+  switch (aLevel) {
+  case LOG_CRITICAL:
+    return LogLevel::Error;
+  case LOG_WARNING:
+    return LogLevel::Warning;
+  case LOG_DEBUG:
+    return LogLevel::Debug;
+  case LOG_DEBUG_PRLOG:
+    return LogLevel::Debug;
+  case LOG_EVERYTHING:
+    return LogLevel::Error;
+  }
+  return LogLevel::Debug;
+}
+#endif
+
+class LoggingPrefs
+{
+public:
+  // Used to choose the level of logging we get.  The higher the number,
+  // the more logging we get.  Value of zero will give you no logging,
+  // 1 just errors, 2 adds warnings and 3 or 4 add debug logging.
+  // In addition to setting the value to 4, you will need to set the
+  // environment variable MOZ_LOG to gfx:4. See mozilla/Logging.h for details.
+  static int32_t sGfxLogLevel;
+};
+
+/// Graphics logging is available in both debug and release builds and is
+/// controlled with a gfx.logging.level preference. If not set, the default
+/// for the preference is 5 in the debug builds, 1 in the release builds.
+///
+/// gfxDebug only works in the debug builds, and is used for information
+/// level messages, helping with debugging.  In addition to only working
+/// in the debug builds, the value of the above preference of 3 or higher
+/// is required.
+///
+/// gfxWarning messages are available in both debug and release builds,
+/// on by default in the debug builds, and off by default in the release builds.
+/// Setting the preference gfx.logging.level to a value of 2 or higher will
+/// show the warnings.
+///
+/// gfxCriticalError is available in debug and release builds by default.
+/// It is only unavailable if gfx.logging.level is set to 0 (or less.)
+/// It outputs the message to stderr or equivalent, like gfxWarning.
+/// In the event of a crash, the crash report is annotated with first and
+/// the last few of these errors, under the key GraphicsCriticalError.
+/// The total number of errors stored in the crash report is controlled
+/// by preference gfx.logging.crash.length.
+///
+/// On platforms that support MOZ_LOGGING, the story is slightly more involved.
+/// In that case, unless gfx.logging.level is set to 4 or higher, the output
+/// is further controlled by the "gfx2d" logging module.  However, in the case
+/// where such module would disable the output, in all but gfxDebug cases,
+/// we will still send a printf.
+
+// The range is due to the values set in Histograms.json
+enum class LogReason : int {
+  MustBeMoreThanThis = -1,
+  // Start.  Do not insert, always add at end.  If you remove items,
+  // make sure the other items retain their values.
+  D3D11InvalidCallDeviceRemoved = 0,
+  D3D11InvalidCall,
+  D3DLockTimeout,
+  D3D10FinalizeFrame,
+  D3D11FinalizeFrame,
+  D3D10SyncLock,
+  D3D11SyncLock,
+  D2D1NoWriteMap,
+  JobStatusError,
+  FilterInputError,
+  FilterInputData, // 10
+  FilterInputRect,
+  FilterInputSet,
+  FilterInputFormat,
+  FilterNodeD2D1Target,
+  FilterNodeD2D1Backend,
+  SourceSurfaceIncompatible,
+  GlyphAllocFailedCairo,
+  GlyphAllocFailedCG,
+  InvalidRect,
+  CannotDraw3D, // 20
+  IncompatibleBasicTexturedEffect,
+  InvalidFont,
+  PAllocTextureBackendMismatch,
+  GetFontFileDataFailed,
+  MessageChannelCloseFailure,
+  MessageChannelInvalidHandle,
+  TextureAliveAfterShutdown,
+  InvalidContext,
+  InvalidCommandList,
+  AsyncTransactionTimeout, // 30
+  TextureCreation,
+  InvalidCacheSurface,
+  AlphaWithBasicClient,
+  UnbalancedClipStack,
+  ProcessingError,
+  NativeFontResourceNotFound,
+  // End
+  MustBeLessThanThis = 101,
+};
+
+struct BasicLogger
+{
+  // For efficiency, this method exists and copies the logic of the
+  // OutputMessage below.  If making any changes here, also make it
+  // in the appropriate places in that method.
+  static bool ShouldOutputMessage(int aLevel) {
+    if (LoggingPrefs::sGfxLogLevel >= aLevel) {
+#if defined(MOZ_WIDGET_ANDROID)
+      return true;
+#else
+#if defined(MOZ_LOGGING)
+      if (MOZ_LOG_TEST(GetGFX2DLog(), PRLogLevelForLevel(aLevel))) {
+        return true;
+      } else
+#endif
+      if ((LoggingPrefs::sGfxLogLevel >= LOG_DEBUG_PRLOG) ||
+                 (aLevel < LOG_DEBUG)) {
+        return true;
+      }
+#endif
+    }
+    return false;
+  }
+
+  // Only for really critical errors.
+  static void CrashAction(LogReason aReason) {}
+
+  static void OutputMessage(const std::string &aString,
+                            int aLevel,
+                            bool aNoNewline) {
+    // This behavior (the higher the preference, the more we log)
+    // is consistent with what prlog does in general.  Note that if prlog
+    // is in the build, but disabled, we will printf if the preferences
+    // requires us to log something (see sGfxLogLevel for the special
+    // treatment of LOG_DEBUG and LOG_DEBUG_PRLOG)
+    //
+    // If making any logic changes to this method, you should probably
+    // make the corresponding change in the ShouldOutputMessage method
+    // above.
+    if (LoggingPrefs::sGfxLogLevel >= aLevel) {
+#if defined(MOZ_WIDGET_ANDROID)
+      printf_stderr("%s%s", aString.c_str(), aNoNewline ? "" : "\n");
+#else
+#if defined(MOZ_LOGGING)
+      if (MOZ_LOG_TEST(GetGFX2DLog(), PRLogLevelForLevel(aLevel))) {
+        PR_LogPrint("%s%s", aString.c_str(), aNoNewline ? "" : "\n");
+      } else
+#endif
+      if ((LoggingPrefs::sGfxLogLevel >= LOG_DEBUG_PRLOG) ||
+                 (aLevel < LOG_DEBUG)) {
+        printf("%s%s", aString.c_str(), aNoNewline ? "" : "\n");
+      }
+#endif
+    }
+  }
+};
+
+struct CriticalLogger {
+  static void OutputMessage(const std::string &aString, int aLevel, bool aNoNewline);
+  static void CrashAction(LogReason aReason);
+};
+
+// The int is the index of the Log call; if the number of logs exceeds some preset
+// capacity we may not get all of them, so the indices help figure out which
+// ones we did save.  The double is expected to be the "TimeDuration", 
+// time in seconds since the process creation.
+typedef mozilla::Tuple<int32_t,std::string,double> LoggingRecordEntry;
+
+// Implement this interface and init the Factory with an instance to
+// forward critical logs.
+typedef std::vector<LoggingRecordEntry> LoggingRecord;
+class LogForwarder {
+public:
+  virtual ~LogForwarder() {}
+  virtual void Log(const std::string &aString) = 0;
+  virtual void CrashAction(LogReason aReason) = 0;
+  virtual bool UpdateStringsVector(const std::string& aString) = 0;
+
+  // Provide a copy of the logs to the caller.
+  virtual LoggingRecord LoggingRecordCopy() = 0;
+};
+
+class NoLog
+{
+public:
+  NoLog() {}
+  ~NoLog() {}
+
+  // No-op
+  MOZ_IMPLICIT NoLog(const NoLog&) {}
+
+  template<typename T>
+  NoLog &operator <<(const T &aLogText) { return *this; }
+};
+
+enum class LogOptions : int {
+  NoNewline = 0x01,
+  AutoPrefix = 0x02,
+  AssertOnCall = 0x04,
+  CrashAction = 0x08,
+};
+
+template<typename T>
+struct Hexa {
+  explicit Hexa(T aVal) : mVal(aVal) {}
+  T mVal;
+};
+template<typename T>
+Hexa<T> hexa(T val) { return Hexa<T>(val); }
+
+template<int L, typename Logger = BasicLogger>
+class Log
+{
+public:
+  // The default is to have the prefix, have the new line, and for critical
+  // logs assert on each call.
+  static int DefaultOptions(bool aWithAssert = true) {
+    return (int(LogOptions::AutoPrefix) |
+            (aWithAssert ? int(LogOptions::AssertOnCall) : 0));
+  }
+
+  // Note that we're calling BasicLogger::ShouldOutputMessage, rather than
+  // Logger::ShouldOutputMessage.  Since we currently don't have a different
+  // version of that method for different loggers, this is OK. Once we do,
+  // change BasicLogger::ShouldOutputMessage to Logger::ShouldOutputMessage.
+  explicit Log(int aOptions = Log::DefaultOptions(L == LOG_CRITICAL),
+               LogReason aReason = LogReason::MustBeMoreThanThis)
+  : mOptions(0)
+  , mLogIt(false)
+  {
+    Init(aOptions, BasicLogger::ShouldOutputMessage(L), aReason);
+  }
+
+  ~Log() {
+    Flush();
+  }
+
+  void Flush() {
+    if (MOZ_LIKELY(!LogIt())) return;
+
+    std::string str = mMessage.str();
+    if (!str.empty()) {
+      WriteLog(str);
+    }
+    mMessage.str("");
+  }
+
+  Log &operator <<(char aChar) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aChar;
+    }
+    return *this;
+  }
+  Log &operator <<(const std::string &aLogText) { 
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aLogText;
+    }
+    return *this;
+  }
+  Log &operator <<(const char aStr[]) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << static_cast<const char*>(aStr);
+    }
+    return *this;
+  }
+  Log &operator <<(bool aBool) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << (aBool ? "true" : "false");
+    }
+    return *this;
+  }
+  Log &operator <<(int aInt) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aInt;
+    }
+    return *this;
+  }
+  Log &operator <<(unsigned int aInt) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aInt;
+    }
+    return *this;
+  }
+  Log &operator <<(long aLong) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aLong;
+    }
+    return *this;
+  }
+  Log &operator <<(unsigned long aLong) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aLong;
+    }
+    return *this;
+  }
+  Log &operator <<(long long aLong) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aLong;
+    }
+    return *this;
+  }
+  Log &operator <<(unsigned long long aLong) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aLong;
+    }
+    return *this;
+  }
+  Log &operator <<(Float aFloat) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aFloat;
+    }
+    return *this;
+  }
+  Log &operator <<(double aDouble) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << aDouble;
+    }
+    return *this;
+  }
+  template <typename T, typename Sub, typename Coord>
+  Log &operator <<(const BasePoint<T, Sub, Coord>& aPoint) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << "Point" << aPoint;
+    }
+    return *this;
+  }
+  template <typename T, typename Sub>
+  Log &operator <<(const BaseSize<T, Sub>& aSize) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << "Size(" << aSize.width << "," << aSize.height << ")";
+    }
+    return *this;
+  }
+  template <typename T, typename Sub, typename Point, typename SizeT, typename Margin>
+  Log &operator <<(const BaseRect<T, Sub, Point, SizeT, Margin>& aRect) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << "Rect" << aRect;
+    }
+    return *this;
+  }
+  Log &operator<<(const Matrix& aMatrix) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << "Matrix(" << aMatrix._11 << " " << aMatrix._12 << " ; " << aMatrix._21 << " " << aMatrix._22 << " ; " << aMatrix._31 << " " << aMatrix._32 << ")";
+    }
+    return *this;
+  }
+  template<typename T>
+  Log &operator<<(Hexa<T> aHex) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      mMessage << std::showbase << std::hex
+               << aHex.mVal
+               << std::noshowbase << std::dec;
+    }
+    return *this;
+  }
+
+  Log& operator<<(SurfaceFormat aFormat) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      switch(aFormat) {
+        case SurfaceFormat::B8G8R8A8:
+          mMessage << "SurfaceFormat::B8G8R8A8";
+          break;
+        case SurfaceFormat::B8G8R8X8:
+          mMessage << "SurfaceFormat::B8G8R8X8";
+          break;
+        case SurfaceFormat::R8G8B8A8:
+          mMessage << "SurfaceFormat::R8G8B8A8";
+          break;
+        case SurfaceFormat::R8G8B8X8:
+          mMessage << "SurfaceFormat::R8G8B8X8";
+          break;
+        case SurfaceFormat::R5G6B5_UINT16:
+          mMessage << "SurfaceFormat::R5G6B5_UINT16";
+          break;
+        case SurfaceFormat::A8:
+          mMessage << "SurfaceFormat::A8";
+          break;
+        case SurfaceFormat::YUV:
+          mMessage << "SurfaceFormat::YUV";
+          break;
+        case SurfaceFormat::UNKNOWN:
+          mMessage << "SurfaceFormat::UNKNOWN";
+          break;
+        default:
+          mMessage << "Invalid SurfaceFormat (" << (int)aFormat << ")";
+          break;
+      }
+    }
+    return *this;
+  }
+
+  Log& operator<<(SurfaceType aType) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      switch(aType) {
+        case SurfaceType::DATA:
+          mMessage << "SurfaceType::DATA";
+          break;
+        case SurfaceType::D2D1_BITMAP:
+          mMessage << "SurfaceType::D2D1_BITMAP";
+          break;
+        case SurfaceType::D2D1_DRAWTARGET:
+          mMessage << "SurfaceType::D2D1_DRAWTARGET";
+          break;
+        case SurfaceType::CAIRO:
+          mMessage << "SurfaceType::CAIRO";
+          break;
+        case SurfaceType::CAIRO_IMAGE:
+          mMessage << "SurfaceType::CAIRO_IMAGE";
+          break;
+        case SurfaceType::COREGRAPHICS_IMAGE:
+          mMessage << "SurfaceType::COREGRAPHICS_IMAGE";
+          break;
+        case SurfaceType::COREGRAPHICS_CGCONTEXT:
+          mMessage << "SurfaceType::COREGRAPHICS_CGCONTEXT";
+          break;
+        case SurfaceType::SKIA:
+          mMessage << "SurfaceType::SKIA";
+          break;
+        case SurfaceType::DUAL_DT:
+          mMessage << "SurfaceType::DUAL_DT";
+          break;
+        case SurfaceType::D2D1_1_IMAGE:
+          mMessage << "SurfaceType::D2D1_1_IMAGE";
+          break;
+        case SurfaceType::RECORDING:
+          mMessage << "SurfaceType::RECORDING";
+          break;
+        case SurfaceType::TILED:
+          mMessage << "SurfaceType::TILED";
+          break;
+        default:
+          mMessage << "Invalid SurfaceType (" << (int)aType << ")";
+          break;
+      }
+    }
+    return *this;
+  }
+
+  inline bool LogIt() const { return mLogIt; }
+  inline bool NoNewline() const { return mOptions & int(LogOptions::NoNewline); }
+  inline bool AutoPrefix() const { return mOptions & int(LogOptions::AutoPrefix); }
+  inline bool ValidReason() const { return (int)mReason > (int)LogReason::MustBeMoreThanThis && (int)mReason < (int)LogReason::MustBeLessThanThis; }
+
+  // We do not want this version to do any work, and stringstream can't be
+  // copied anyway.  It does come in handy for the "Once" macro defined below.
+  MOZ_IMPLICIT Log(const Log& log) { Init(log.mOptions, false, log.mReason); }
+
+private:
+  // Initialization common to two constructors
+  void Init(int aOptions, bool aLogIt, LogReason aReason) {
+    mOptions = aOptions;
+    mReason = aReason;
+    mLogIt = aLogIt;
+    if (mLogIt) {
+      if (AutoPrefix()) {
+        if (mOptions & int(LogOptions::AssertOnCall)) {
+          mMessage << "[GFX" << L;
+        } else {
+          mMessage << "[GFX" << L << "-";
+        }
+      }
+      if ((mOptions & int(LogOptions::CrashAction)) && ValidReason()) {
+        mMessage << " " << (int)mReason;
+      }
+      if (AutoPrefix()) {
+        mMessage << "]: ";
+      }
+    }
+  }
+
+  void WriteLog(const std::string &aString) {
+    if (MOZ_UNLIKELY(LogIt())) {
+      Logger::OutputMessage(aString, L, NoNewline());
+      // Assert if required.  We don't have a three parameter MOZ_ASSERT
+      // so use the underlying functions instead (see bug 1281702):
+#ifdef DEBUG
+      if (mOptions & int(LogOptions::AssertOnCall)) {
+        MOZ_ReportAssertionFailure(aString.c_str(), __FILE__, __LINE__);
+        MOZ_CRASH("GFX: An assert from the graphics logger");
+      }
+#endif
+      if ((mOptions & int(LogOptions::CrashAction)) && ValidReason()) {
+        Logger::CrashAction(mReason);
+      }
+    }
+  }
+
+  std::stringstream mMessage;
+  int mOptions;
+  LogReason mReason;
+  bool mLogIt;
+};
+
+typedef Log<LOG_DEBUG> DebugLog;
+typedef Log<LOG_WARNING> WarningLog;
+typedef Log<LOG_CRITICAL, CriticalLogger> CriticalLog;
+
+// Macro to glue names to get us less chance of name clashing.
+#if defined GFX_LOGGING_GLUE1 || defined GFX_LOGGING_GLUE
+#error "Clash of the macro GFX_LOGGING_GLUE1 or GFX_LOGGING_GLUE"
+#endif
+#define GFX_LOGGING_GLUE1(x, y)  x##y
+#define GFX_LOGGING_GLUE(x, y)   GFX_LOGGING_GLUE1(x, y)
+
+// This log goes into crash reports, use with care.
+#define gfxCriticalError mozilla::gfx::CriticalLog
+#define gfxCriticalErrorOnce static gfxCriticalError GFX_LOGGING_GLUE(sOnceAtLine,__LINE__) = gfxCriticalError
+
+// This is a shortcut for errors we want logged in crash reports/about support
+// but we do not want asserting.  These are available in all builds, so it is
+// not worth trying to do magic to avoid matching the syntax of gfxCriticalError.
+// So, this one is used as
+// gfxCriticalNote << "Something to report and not assert";
+// while the critical error is
+// gfxCriticalError() << "Something to report and assert";
+#define gfxCriticalNote gfxCriticalError(gfxCriticalError::DefaultOptions(false))
+#define gfxCriticalNoteOnce static gfxCriticalError GFX_LOGGING_GLUE(sOnceAtLine,__LINE__) = gfxCriticalNote
+
+// The "once" versions will only trigger the first time through. You can do this:
+// gfxCriticalErrorOnce() << "This message only shows up once;
+// instead of the usual:
+// static bool firstTime = true;
+// if (firstTime) {
+//   firstTime = false;
+//   gfxCriticalError() << "This message only shows up once;
+// }
+#if defined(DEBUG)
+#define gfxDebug mozilla::gfx::DebugLog
+#define gfxDebugOnce static gfxDebug GFX_LOGGING_GLUE(sOnceAtLine,__LINE__) = gfxDebug
+#else
+#define gfxDebug if (1) ; else mozilla::gfx::NoLog
+#define gfxDebugOnce if (1) ; else mozilla::gfx::NoLog
+#endif
+
+// Have gfxWarning available (behind a runtime preference)
+#define gfxWarning mozilla::gfx::WarningLog
+#define gfxWarningOnce static gfxWarning GFX_LOGGING_GLUE(sOnceAtLine,__LINE__) = gfxWarning
+
+// In the debug build, this is equivalent to the default gfxCriticalError.
+// In the non-debug build, on nightly and dev edition, it will MOZ_CRASH.
+// On beta and release versions, it will telemetry count, but proceed.
+//
+// You should create a (new) enum in the LogReason and use it for the reason
+// parameter to ensure uniqueness.
+#define gfxDevCrash(reason) gfxCriticalError(int(gfx::LogOptions::AutoPrefix) | int(gfx::LogOptions::AssertOnCall) | int(gfx::LogOptions::CrashAction), (reason))
+
+// See nsDebug.h and the NS_WARN_IF macro
+
+#ifdef __cplusplus
+ // For now, have MOZ2D_ERROR_IF available in debug and non-debug builds
+inline bool MOZ2D_error_if_impl(bool aCondition, const char* aExpr,
+                                const char* aFile, int32_t aLine)
+{
+  if (MOZ_UNLIKELY(aCondition)) {
+    gfxCriticalError() << aExpr << " at " << aFile << ":" << aLine;
+  }
+  return aCondition;
+}
+#define MOZ2D_ERROR_IF(condition) \
+  MOZ2D_error_if_impl(condition, #condition, __FILE__, __LINE__)
+
+#ifdef DEBUG
+inline bool MOZ2D_warn_if_impl(bool aCondition, const char* aExpr,
+                               const char* aFile, int32_t aLine)
+{
+  if (MOZ_UNLIKELY(aCondition)) {
+    gfxWarning() << aExpr << " at " << aFile << ":" << aLine;
+  }
+  return aCondition;
+}
+#define MOZ2D_WARN_IF(condition) \
+  MOZ2D_warn_if_impl(condition, #condition, __FILE__, __LINE__)
+#else
+#define MOZ2D_WARN_IF(condition) (bool)(condition)
+#endif
+#endif
+
+const int INDENT_PER_LEVEL = 2;
+
+class TreeLog
+{
+public:
+  explicit TreeLog(const std::string& aPrefix = "")
+        : mLog(int(LogOptions::NoNewline)),
+          mPrefix(aPrefix),
+          mDepth(0),
+          mStartOfLine(true),
+          mConditionedOnPref(false),
+          mPrefFunction(nullptr) {}
+
+  template <typename T>
+  TreeLog& operator<<(const T& aObject) {
+    if (mConditionedOnPref && !mPrefFunction()) {
+      return *this;
+    }
+    if (mStartOfLine) {
+      mLog << '[' << mPrefix << "] " << std::string(mDepth * INDENT_PER_LEVEL, ' ');
+      mStartOfLine = false;
+    }
+    mLog << aObject;
+    if (EndsInNewline(aObject)) {
+      // Don't indent right here as the user may change the indent
+      // between now and the first output to the next line.
+      mLog.Flush();
+      mStartOfLine = true;
+    }
+    return *this;
+  }
+
+  void IncreaseIndent() { ++mDepth; }
+  void DecreaseIndent() {
+    MOZ_ASSERT(mDepth > 0);
+    --mDepth;
+  }
+
+  void ConditionOnPrefFunction(bool(*aPrefFunction)()) {
+    mConditionedOnPref = true;
+    mPrefFunction = aPrefFunction;
+  }
+private:
+  Log<LOG_DEBUG> mLog;
+  std::string mPrefix;
+  uint32_t mDepth;
+  bool mStartOfLine;
+  bool mConditionedOnPref;
+  bool (*mPrefFunction)();
+
+  template <typename T>
+  static bool EndsInNewline(const T& aObject) {
+    return false;
+  }
+
+  static bool EndsInNewline(const std::string& aString) {
+    return !aString.empty() && aString[aString.length() - 1] == '\n';
+  }
+
+  static bool EndsInNewline(char aChar) {
+    return aChar == '\n';
+  }
+
+  static bool EndsInNewline(const char* aString) {
+    return EndsInNewline(std::string(aString));
+  }
+};
+
+class TreeAutoIndent
+{
+public:
+  explicit TreeAutoIndent(TreeLog& aTreeLog) : mTreeLog(aTreeLog) {
+    mTreeLog.IncreaseIndent();
+  }
+
+  TreeAutoIndent(const TreeAutoIndent& aTreeAutoIndent) :
+      TreeAutoIndent(aTreeAutoIndent.mTreeLog) {
+    mTreeLog.IncreaseIndent();
+  }
+
+  TreeAutoIndent& operator=(const TreeAutoIndent& aTreeAutoIndent) = delete;
+
+  ~TreeAutoIndent() {
+    mTreeLog.DecreaseIndent();
+  }
+private:
+  TreeLog& mTreeLog;
+};
+
+} // namespace gfx
+} // namespace mozilla
+
+#endif /* MOZILLA_GFX_LOGGING_H_ */