Revert of Remove SkThread.h, include SkMutex.h or SkAtomics.h as appropriate. (patchset #4 id:60001 of https://codereview.chromium.org/1215393002/)

Reason for revert:
Breaking the roll.

E.g. on android_chromium_gn_compile_dbg:

FAILED: /b/build/goma/gomacc ../../third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-g++ -MMD -MF obj/skia/ext/libskia.SkMemory_new_handler.o.d -DV8_DEPRECATION_WARNINGS -DCLD_VERSION=1 -DENABLE_NOTIFICATIONS -DENABLE_BROWSER_CDMS -DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1 -DDONT_EMBED_BUILD_METADATA -DUSE_OPENSSL=1 -DUSE_OPENSSL_CERTS=1 -DNO_TCMALLOC -DDISABLE_NACL -DENABLE_CONFIGURATION_POLICY -DENABLE_SUPERVISED_USERS=1 -DENABLE_AUTOFILL_DIALOG=1 -DUSE_PROPRIETARY_CODECS -DV8_USE_EXTERNAL_STARTUP_DATA -DVIDEO_HOLE=1 -DMOBILE_SAFE_BROWSING -DSAFE_BROWSING_SERVICE -DCHROMIUM_BUILD -D_FILE_OFFSET_BITS=64 -DANDROID -DHAVE_SYS_UIO_H -DCOMPONENT_BUILD -D__GNU_SOURCE=1 -D_DEBUG -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1 -DSKIA_IMPLEMENTATION=1 -DSK_ARM_HAS_OPTIONAL_NEON -DSK_GAMMA_APPLY_TO_A8 -DSK_GAMMA_EXPONENT=1.4 -DSK_GAMMA_CONTRAST=0.0 -DSK_DEFAULT_FONT_CACHE_LIMIT=1048576 -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DSKIA_DLL -DGR_GL_IGNORE_ES3_MSAA=0 -DSK_SUPPORT_GPU=1 -DSK_BUILD_FOR_ANDROID -DUSE_CHROMIUM_SKIA -DXML_STATIC -I../.. -Igen -I../../third_party/skia/include/private -I../../third_party/skia/src/core -I../../third_party/skia/src/image -I../../third_party/skia/src/opts -I../../third_party/skia/src/pdf -I../../third_party/skia/src/ports -I../../third_party/skia/src/sfnt -I../../third_party/skia/src/utils -I../../third_party/skia/src/lazy -I../../skia/config -I../../skia/ext -I../../third_party/skia/include/c -I../../third_party/skia/include/config -I../../third_party/skia/include/core -I../../third_party/skia/include/effects -I../../third_party/skia/include/images -I../../third_party/skia/include/lazy -I../../third_party/skia/include/pathops -I../../third_party/skia/include/pdf -I../../third_party/skia/include/pipe -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../third_party/skia/include/gpu -I../../third_party/skia/src/gpu -I../../third_party/zlib -I../../third_party/expat/files/lib -I../../third_party/freetype-android/include -I../../third_party/freetype-android/src/include -I../../third_party/android_tools/ndk/sources/android/cpufeatures -fno-strict-aliasing -march=armv7-a -mfloat-abi=softfp -mtune=generic-armv7-a -mthumb -mthumb-interwork -fno-tree-sra -fno-caller-saves -funwind-tables -fPIC -pipe -ffunction-sections -funwind-tables -fno-short-enums -finline-limit=64 -mfpu=vfpv3-d16 -isystem../../third_party/android_tools/ndk/sources/cxx-stl/llvm-libc++/libcxx/include -isystem../../third_party/android_tools/ndk/sources/cxx-stl/llvm-libc++abi/libcxxabi/include -isystem../../third_party/android_tools/ndk/sources/android/support/include -fvisibility=hidden --sysroot=/b/build/slave/android_chromium_gn/build/src/third_party/android_tools/ndk/platforms/android-16/arch-arm -Os -fdata-sections -ffunction-sections -fomit-frame-pointer -g1 -Wno-format -Wendif-labels -Werror -Wno-missing-field-initializers -Wno-unused-parameter -Wno-psabi -Wno-extra -Wno-ignored-qualifiers -Wno-type-limits -Wno-unused-local-typedefs -fno-threadsafe-statics -fvisibility-inlines-hidden -std=gnu++11 -fno-rtti -fno-exceptions -Wno-deprecated -Wno-narrowing -Wno-literal-suffix -Wno-error=c++0x-compat -Wno-non-virtual-dtor -Wno-sign-promo -c ../../skia/ext/SkMemory_new_handler.cpp -o obj/skia/ext/libskia.SkMemory_new_handler.o
../../skia/ext/SkMemory_new_handler.cpp:12:52: fatal error: third_party/skia/include/core/SkThread.h: No such file or directory
 #include "third_party/skia/include/core/SkThread.h"

Original issue's description:
> Remove SkThread.h, include SkMutex.h or SkAtomics.h as appropriate.
>
> SkThread.h doesn't do anything anymore execept include those two,
> and thankfully, it doesn't seem to be mentioned outside Skia.
>
> No public API changes.
> TBR=reed@google.com
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/c50acf2321d7a934c80d754e9cbe936dfb8eb4cc

TBR=mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1214603003

56 files changed, 105 insertions, 94 deletions

diff --git a/bench/MutexBench.cpp b/bench/MutexBench.cpp
index 8d7eb98546..7fd8fabba1 100644
--- a/bench/MutexBench.cpp
+++ b/bench/MutexBench.cpp
@@ -5,7 +5,7 @@
  * found in the LICENSE file.
  */
 #include "Benchmark.h"
-#include "SkMutex.h"
+#include "SkThread.h"
 
 class MutexBench : public Benchmark {
 public:
diff --git a/bench/RefCntBench.cpp b/bench/RefCntBench.cpp
index ee5d74622e..78b02edb60 100644
--- a/bench/RefCntBench.cpp
+++ b/bench/RefCntBench.cpp
@@ -6,8 +6,8 @@
  */
 #include <memory>
 #include "Benchmark.h"
-#include "SkAtomics.h"
 #include "SkRefCnt.h"
+#include "SkThread.h"
 #include "SkWeakRefCnt.h"
 
 enum {
diff --git a/dm/DM.cpp b/dm/DM.cpp
index 6b3464157b..c3a4272509 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -18,7 +18,6 @@
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
 #include "SkMD5.h"
-#include "SkMutex.h"
 #include "SkOSFile.h"
 #include "SkTHash.h"
 #include "SkTaskGroup.h"
diff --git a/dm/DMJsonWriter.cpp b/dm/DMJsonWriter.cpp
index 5317567d68..04ae2cea8a 100644
--- a/dm/DMJsonWriter.cpp
+++ b/dm/DMJsonWriter.cpp
@@ -11,10 +11,10 @@
 #include "SkCommonFlags.h"
 #include "SkData.h"
 #include "SkJSONCPP.h"
-#include "SkMutex.h"
 #include "SkOSFile.h"
 #include "SkStream.h"
 #include "SkTArray.h"
+#include "SkThread.h"
 
 namespace DM {
 
diff --git a/gyp/core.gypi b/gyp/core.gypi
index 10149d878a..edc77e17c6 100644
--- a/gyp/core.gypi
+++ b/gyp/core.gypi
@@ -323,6 +323,7 @@
         '<(skia_include_path)/core/SkTSearch.h',
         '<(skia_include_path)/core/SkTemplates.h',
         '<(skia_include_path)/core/SkTextBlob.h',
+        '<(skia_include_path)/core/SkThread.h',
         '<(skia_include_path)/core/SkTime.h',
         '<(skia_include_path)/core/SkTLazy.h',
         '<(skia_include_path)/core/SkTypeface.h',
diff --git a/include/core/SkThread.h b/include/core/SkThread.h
new file mode 100644
index 0000000000..67e0b72d1c
--- /dev/null
+++ b/include/core/SkThread.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkThread_DEFINED
+#define SkThread_DEFINED
+
+// TODO: delete this file, or maybe move the definition of SkThread here.
+
+#include "SkAtomics.h"
+#include "SkMutex.h"
+
+#endif
diff --git a/include/core/SkWeakRefCnt.h b/include/core/SkWeakRefCnt.h
index a550951970..0798f4e509 100644
--- a/include/core/SkWeakRefCnt.h
+++ b/include/core/SkWeakRefCnt.h
@@ -9,7 +9,7 @@
 #define SkWeakRefCnt_DEFINED
 
 #include "SkRefCnt.h"
-#include "SkAtomics.h"
+#include "SkThread.h"
 
 /** \class SkWeakRefCnt
 
diff --git a/include/ports/SkFontMgr_indirect.h b/include/ports/SkFontMgr_indirect.h
index 96ba3632d5..0977eea26a 100644
--- a/include/ports/SkFontMgr_indirect.h
+++ b/include/ports/SkFontMgr_indirect.h
@@ -11,7 +11,6 @@
 #include "SkDataTable.h"
 #include "SkFontMgr.h"
 #include "SkFontStyle.h"
-#include "SkMutex.h"
 #include "SkRemotableFontMgr.h"
 #include "SkTArray.h"
 #include "SkTypeface.h"
diff --git a/src/core/SkAAClip.cpp b/src/core/SkAAClip.cpp
index 902b87a6c7..19e94c8c86 100644
--- a/src/core/SkAAClip.cpp
+++ b/src/core/SkAAClip.cpp
@@ -7,11 +7,11 @@
  */
 
 #include "SkAAClip.h"
-#include "SkAtomics.h"
 #include "SkBlitter.h"
 #include "SkColorPriv.h"
 #include "SkPath.h"
 #include "SkScan.h"
+#include "SkThread.h"
 #include "SkUtils.h"
 
 class AutoAAClipValidate {
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index aa26bdcab3..8f799125e4 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -7,7 +7,6 @@
  */
 
 
-#include "SkAtomics.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
 #include "SkDither.h"
@@ -15,13 +14,14 @@
 #include "SkImagePriv.h"
 #include "SkMallocPixelRef.h"
 #include "SkMask.h"
-#include "SkPackBits.h"
-#include "SkPixelRef.h"
 #include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+#include "SkPixelRef.h"
+#include "SkThread.h"
 #include "SkUnPreMultiply.h"
 #include "SkUtils.h"
 #include "SkValidationUtils.h"
-#include "SkWriteBuffer.h"
+#include "SkPackBits.h"
 #include <new>
 
 static bool reset_return_false(SkBitmap* bm) {
diff --git a/src/core/SkBitmapHeap.h b/src/core/SkBitmapHeap.h
index 259d947923..07f629c77a 100644
--- a/src/core/SkBitmapHeap.h
+++ b/src/core/SkBitmapHeap.h
@@ -12,7 +12,7 @@
 #include "SkFlattenable.h"
 #include "SkRefCnt.h"
 #include "SkTDArray.h"
-#include "SkAtomics.h"
+#include "SkThread.h"
 
 /**
  * SkBitmapHeapEntry provides users of SkBitmapHeap (using internal storage) with a means to...
@@ -52,7 +52,7 @@ private:
 
 class SkBitmapHeapReader : public SkRefCnt {
 public:
-
+    
 
     SkBitmapHeapReader() : INHERITED() {}
     virtual SkBitmap* getBitmap(int32_t slot) const = 0;
@@ -69,7 +69,7 @@ class SkBitmapHeap : public SkBitmapHeapReader {
 public:
     class ExternalStorage : public SkRefCnt {
      public:
-
+        
 
         virtual bool insert(const SkBitmap& bitmap, int32_t slot) = 0;
 
diff --git a/src/core/SkCachedData.h b/src/core/SkCachedData.h
index 6493a75e0b..886ca3e7e4 100644
--- a/src/core/SkCachedData.h
+++ b/src/core/SkCachedData.h
@@ -8,7 +8,7 @@
 #ifndef SkCachedData_DEFINED
 #define SkCachedData_DEFINED
 
-#include "SkMutex.h"
+#include "SkThread.h"
 
 class SkDiscardableMemory;
 
@@ -78,7 +78,7 @@ public:
 #else
     void validate() const {}
 #endif
-
+    
    /*
      *  Attaching a data to to a SkResourceCache (only one at a time) enables the data to be
      *  unlocked when the cache is the only owner, thus freeing it to be purged (assuming the
diff --git a/src/core/SkClipStack.cpp b/src/core/SkClipStack.cpp
index c4c68ced08..e0c3db01ba 100644
--- a/src/core/SkClipStack.cpp
+++ b/src/core/SkClipStack.cpp
@@ -5,11 +5,11 @@
  * found in the LICENSE file.
  */
 
-#include "SkAtomics.h"
 #include "SkCanvas.h"
 #include "SkClipStack.h"
 #include "SkPath.h"
 #include "SkPathOps.h"
+#include "SkThread.h"
 
 #include <new>
 
diff --git a/src/core/SkDeviceProfile.cpp b/src/core/SkDeviceProfile.cpp
index 188e12b4b0..8d60151f6f 100644
--- a/src/core/SkDeviceProfile.cpp
+++ b/src/core/SkDeviceProfile.cpp
@@ -7,7 +7,7 @@
 
 
 #include "SkDeviceProfile.h"
-#include "SkMutex.h"
+#include "SkThread.h"
 
 #define DEFAULT_GAMMAEXP        2.2f
 #define DEFAULT_CONTRASTSCALE   0.5f
diff --git a/src/core/SkDrawable.cpp b/src/core/SkDrawable.cpp
index 73f5779b7d..64fefd2f1c 100644
--- a/src/core/SkDrawable.cpp
+++ b/src/core/SkDrawable.cpp
@@ -5,9 +5,9 @@
  * found in the LICENSE file.
  */
 
-#include "SkAtomics.h"
 #include "SkCanvas.h"
 #include "SkDrawable.h"
+#include "SkThread.h"
 
 static int32_t next_generation_id() {
     static int32_t gCanvasDrawableGenerationID;
diff --git a/src/core/SkGlyphCache.cpp b/src/core/SkGlyphCache.cpp
index 6ae17b1074..ec342275cc 100755
--- a/src/core/SkGlyphCache.cpp
+++ b/src/core/SkGlyphCache.cpp
@@ -9,11 +9,10 @@
 #include "SkGlyphCache_Globals.h"
 #include "SkGraphics.h"
 #include "SkLazyPtr.h"
-#include "SkMutex.h"
 #include "SkPaint.h"
 #include "SkPath.h"
-#include "SkTLS.h"
 #include "SkTemplates.h"
+#include "SkTLS.h"
 #include "SkTypeface.h"
 
 //#define SPEW_PURGE_STATUS
@@ -418,6 +417,8 @@ void SkGlyphCache::invokeAndRemoveAuxProcs() {
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 
+#include "SkThread.h"
+
 size_t SkGlyphCache_Globals::setCacheSizeLimit(size_t newLimit) {
     static const size_t minLimit = 256 * 1024;
     if (newLimit < minLimit) {
diff --git a/src/core/SkGlyphCache_Globals.h b/src/core/SkGlyphCache_Globals.h
index e8f950f611..4bd607c598 100644
--- a/src/core/SkGlyphCache_Globals.h
+++ b/src/core/SkGlyphCache_Globals.h
@@ -9,7 +9,6 @@
 #define SkGlyphCache_Globals_DEFINED
 
 #include "SkGlyphCache.h"
-#include "SkMutex.h"
 #include "SkTLS.h"
 
 #ifndef SK_DEFAULT_FONT_CACHE_COUNT_LIMIT
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 394d8b20e7..7233ec6706 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -13,13 +13,12 @@
 #include "SkDevice.h"
 #include "SkLazyPtr.h"
 #include "SkMatrixImageFilter.h"
-#include "SkMutex.h"
 #include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
 #include "SkRect.h"
 #include "SkTDynamicHash.h"
 #include "SkTInternalLList.h"
 #include "SkValidationUtils.h"
-#include "SkWriteBuffer.h"
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrDrawContext.h"
@@ -29,9 +28,9 @@
 
 #ifdef SK_BUILD_FOR_IOS
   enum { kDefaultCacheSize = 2 * 1024 * 1024 };
-#else
+#else 
   enum { kDefaultCacheSize = 128 * 1024 * 1024 };
-#endif
+#endif 
 
 static int32_t next_image_filter_unique_id() {
     static int32_t gImageFilterUniqueID;
@@ -547,4 +546,4 @@ bool SkImageFilter::Proxy::filterImage(const SkImageFilter* filter, const SkBitm
                                        SkBitmap* result, SkIPoint* offset) {
     return fDevice->filterImage(filter, src, ctx, result, offset);
 }
-
+    
diff --git a/src/core/SkMessageBus.h b/src/core/SkMessageBus.h
index 6f032a1fe2..b25ab80798 100644
--- a/src/core/SkMessageBus.h
+++ b/src/core/SkMessageBus.h
@@ -9,9 +9,9 @@
 #define SkMessageBus_DEFINED
 
 #include "SkLazyPtr.h"
-#include "SkMutex.h"
 #include "SkTArray.h"
 #include "SkTDArray.h"
+#include "SkThread.h"
 #include "SkTypes.h"
 
 template <typename Message>
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index eae8ec70e5..f40aeff727 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -17,7 +17,6 @@
 #include "SkImageFilter.h"
 #include "SkMaskFilter.h"
 #include "SkMaskGamma.h"
-#include "SkMutex.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkPaintDefaults.h"
diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index 9381f48f3b..daac0772dc 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -12,6 +12,7 @@
 #include "SkPathPriv.h"
 #include "SkPathRef.h"
 #include "SkRRect.h"
+#include "SkThread.h"
 
 ////////////////////////////////////////////////////////////////////////////
 
@@ -1880,7 +1881,7 @@ size_t SkPath::readFromMemory(const void* storage, size_t length) {
     }
 
     unsigned version = packed & 0xFF;
-
+    
     fConvexity = (packed >> kConvexity_SerializationShift) & 0xFF;
     fFillType = (packed >> kFillType_SerializationShift) & 0xFF;
     uint8_t dir = (packed >> kDirection_SerializationShift) & 0x3;
diff --git a/src/core/SkPixelRef.cpp b/src/core/SkPixelRef.cpp
index 082435f8c7..6e1f5c6417 100644
--- a/src/core/SkPixelRef.cpp
+++ b/src/core/SkPixelRef.cpp
@@ -6,8 +6,8 @@
  */
 
 #include "SkBitmapCache.h"
-#include "SkMutex.h"
 #include "SkPixelRef.h"
+#include "SkThread.h"
 #include "SkTraceEvent.h"
 
 //#define SK_SUPPORT_LEGACY_UNBALANCED_PIXELREF_LOCKCOUNT
diff --git a/src/core/SkRegion.cpp b/src/core/SkRegion.cpp
index 05ba4f46a2..24d7248582 100644
--- a/src/core/SkRegion.cpp
+++ b/src/core/SkRegion.cpp
@@ -7,9 +7,9 @@
  */
 
 
-#include "SkAtomics.h"
 #include "SkRegionPriv.h"
 #include "SkTemplates.h"
+#include "SkThread.h"
 #include "SkUtils.h"
 
 /* Region Layout
diff --git a/src/core/SkRegionPriv.h b/src/core/SkRegionPriv.h
index 9ddefc06cc..00feedeab8 100644
--- a/src/core/SkRegionPriv.h
+++ b/src/core/SkRegionPriv.h
@@ -11,7 +11,7 @@
 #define SkRegionPriv_DEFINED
 
 #include "SkRegion.h"
-#include "SkAtomics.h"
+#include "SkThread.h"
 
 #define assert_sentinel(value, isSentinel) \
     SkASSERT(((value) == SkRegion::kRunTypeSentinel) == isSentinel)
diff --git a/src/core/SkResourceCache.cpp b/src/core/SkResourceCache.cpp
index 6c76d350c3..f0fe72113e 100644
--- a/src/core/SkResourceCache.cpp
+++ b/src/core/SkResourceCache.cpp
@@ -8,7 +8,6 @@
 #include "SkChecksum.h"
 #include "SkMessageBus.h"
 #include "SkMipMap.h"
-#include "SkMutex.h"
 #include "SkPixelRef.h"
 #include "SkResourceCache.h"
 
@@ -75,7 +74,7 @@ void SkResourceCache::init() {
 
 class SkOneShotDiscardablePixelRef : public SkPixelRef {
 public:
-
+    
     // Ownership of the discardablememory is transfered to the pixelref
     SkOneShotDiscardablePixelRef(const SkImageInfo&, SkDiscardableMemory*, size_t rowBytes);
     ~SkOneShotDiscardablePixelRef();
@@ -237,7 +236,7 @@ static bool gDumpCacheTransactions;
 
 void SkResourceCache::add(Rec* rec) {
     this->checkMessages();
-
+    
     SkASSERT(rec);
     // See if we already have this key (racy inserts, etc.)
     Rec* existing = fHash->find(rec->getKey());
@@ -245,7 +244,7 @@ void SkResourceCache::add(Rec* rec) {
         SkDELETE(rec);
         return;
     }
-
+    
     this->addToHead(rec);
     fHash->add(rec);
 
@@ -358,7 +357,7 @@ size_t SkResourceCache::setTotalByteLimit(size_t newLimit) {
 
 SkCachedData* SkResourceCache::newCachedData(size_t bytes) {
     this->checkMessages();
-
+    
     if (fDiscardableFactory) {
         SkDiscardableMemory* dm = fDiscardableFactory(bytes);
         return dm ? SkNEW_ARGS(SkCachedData, (bytes, dm)) : NULL;
@@ -516,6 +515,8 @@ void SkResourceCache::checkMessages() {
 
 ///////////////////////////////////////////////////////////////////////////////
 
+#include "SkThread.h"
+
 SK_DECLARE_STATIC_MUTEX(gMutex);
 static SkResourceCache* gResourceCache = NULL;
 static void cleanup_gResourceCache() {
diff --git a/src/core/SkScalerContext.cpp b/src/core/SkScalerContext.cpp
index b765aad97c..4ce42ddc07 100644
--- a/src/core/SkScalerContext.cpp
+++ b/src/core/SkScalerContext.cpp
@@ -21,6 +21,7 @@
 #include "SkRasterizer.h"
 #include "SkRasterClip.h"
 #include "SkStroke.h"
+#include "SkThread.h"
 
 #define ComputeBWRowBytes(width)        (((unsigned)(width) + 7) >> 3)
 
diff --git a/src/core/SkShader.cpp b/src/core/SkShader.cpp
index 32984960ab..f146345f9a 100644
--- a/src/core/SkShader.cpp
+++ b/src/core/SkShader.cpp
@@ -5,17 +5,17 @@
  * found in the LICENSE file.
  */
 
-#include "SkAtomics.h"
 #include "SkBitmapProcShader.h"
 #include "SkColorShader.h"
 #include "SkEmptyShader.h"
+#include "SkReadBuffer.h"
 #include "SkMallocPixelRef.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkPictureShader.h"
-#include "SkReadBuffer.h"
 #include "SkScalar.h"
 #include "SkShader.h"
+#include "SkThread.h"
 #include "SkWriteBuffer.h"
 
 //#define SK_TRACK_SHADER_LIFETIME
diff --git a/src/core/SkString.cpp b/src/core/SkString.cpp
index 5c63a8b515..c10347dad1 100644
--- a/src/core/SkString.cpp
+++ b/src/core/SkString.cpp
@@ -7,9 +7,9 @@
  */
 
 
-#include "SkAtomics.h"
-#include "SkFixed.h"
 #include "SkString.h"
+#include "SkFixed.h"
+#include "SkThread.h"
 #include "SkUtils.h"
 #include <stdarg.h>
 #include <stdio.h>
diff --git a/src/core/SkTLS.cpp b/src/core/SkTLS.cpp
index 346fed80ce..3f78a2434c 100755
--- a/src/core/SkTLS.cpp
+++ b/src/core/SkTLS.cpp
@@ -1,10 +1,3 @@
-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
 #include "SkTLS.h"
 
 // enable to help debug TLS storage
@@ -12,7 +5,7 @@
 
 
 #ifdef SK_TRACE_TLS_LIFETIME
-    #include "SkAtomics.h"
+    #include "SkThread.h"
     static int32_t gTLSRecCount;
 #endif
 
diff --git a/src/core/SkTypeface.cpp b/src/core/SkTypeface.cpp
index c94e22f2bc..2c7db68d87 100644
--- a/src/core/SkTypeface.cpp
+++ b/src/core/SkTypeface.cpp
@@ -10,7 +10,6 @@
 #include "SkFontDescriptor.h"
 #include "SkFontMgr.h"
 #include "SkLazyPtr.h"
-#include "SkMutex.h"
 #include "SkOTTable_OS_2.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
diff --git a/src/core/SkTypefaceCache.cpp b/src/core/SkTypefaceCache.cpp
index 49779fcbe3..f253b60523 100644
--- a/src/core/SkTypefaceCache.cpp
+++ b/src/core/SkTypefaceCache.cpp
@@ -9,8 +9,7 @@
 
 
 #include "SkTypefaceCache.h"
-#include "SkAtomics.h"
-#include "SkMutex.h"
+#include "SkThread.h"
 
 #define TYPEFACE_CACHE_LIMIT    1024
 
diff --git a/src/fonts/SkFontMgr_fontconfig.cpp b/src/fonts/SkFontMgr_fontconfig.cpp
index 0873aa105b..9294990c98 100644
--- a/src/fonts/SkFontMgr_fontconfig.cpp
+++ b/src/fonts/SkFontMgr_fontconfig.cpp
@@ -5,14 +5,14 @@
  * found in the LICENSE file.
  */
 
-#include "SkFontConfigInterface.h"
-#include "SkFontConfigTypeface.h"
 #include "SkFontMgr.h"
 #include "SkFontStyle.h"
+#include "SkFontConfigInterface.h"
+#include "SkFontConfigTypeface.h"
 #include "SkMath.h"
-#include "SkMutex.h"
 #include "SkString.h"
 #include "SkTDArray.h"
+#include "SkThread.h"
 
 // for now we pull these in directly. eventually we will solely rely on the
 // SkFontConfigInterface instance.
diff --git a/src/fonts/SkTestScalerContext.cpp b/src/fonts/SkTestScalerContext.cpp
index 50706f66c3..28b53b3a15 100644
--- a/src/fonts/SkTestScalerContext.cpp
+++ b/src/fonts/SkTestScalerContext.cpp
@@ -42,7 +42,7 @@ SkTestFont::~SkTestFont() {
 
 #ifdef SK_DEBUG
 
-#include "SkMutex.h"
+#include "SkThread.h"
 SK_DECLARE_STATIC_MUTEX(gUsedCharsMutex);
 
 #endif
diff --git a/src/gpu/GrBatch.h b/src/gpu/GrBatch.h
index 21dc3d21c8..eb385635bc 100644
--- a/src/gpu/GrBatch.h
+++ b/src/gpu/GrBatch.h
@@ -12,8 +12,8 @@
 #include "GrBatchTarget.h"
 #include "GrGeometryProcessor.h"
 #include "GrVertices.h"
-#include "SkAtomics.h"
 #include "SkRefCnt.h"
+#include "SkThread.h"
 #include "SkTypes.h"
 
 class GrGpu;
@@ -39,7 +39,7 @@ struct GrInitInvariantOutput;
 
 class GrBatch : public SkRefCnt {
 public:
-
+    
     GrBatch() : fClassID(kIllegalBatchClassID), fNumberOfDraws(0) { SkDEBUGCODE(fUsed = false;) }
     virtual ~GrBatch() {}
 
diff --git a/src/gpu/gl/GrGLNoOpInterface.cpp b/src/gpu/gl/GrGLNoOpInterface.cpp
index f47f254424..396eaa46ea 100644
--- a/src/gpu/gl/GrGLNoOpInterface.cpp
+++ b/src/gpu/gl/GrGLNoOpInterface.cpp
@@ -6,8 +6,8 @@
  */
 
 #include "GrGLNoOpInterface.h"
-#include "SkMutex.h"
 #include "SkString.h"
+#include "SkThread.h"
 
 // the OpenGLES 2.0 spec says this must be >= 128
 static const GrGLint kDefaultMaxVertexUniformVectors = 128;
diff --git a/src/lazy/SkDiscardableMemoryPool.cpp b/src/lazy/SkDiscardableMemoryPool.cpp
index 70072c6b8c..5b9d87ff2f 100644
--- a/src/lazy/SkDiscardableMemoryPool.cpp
+++ b/src/lazy/SkDiscardableMemoryPool.cpp
@@ -9,8 +9,8 @@
 #include "SkDiscardableMemoryPool.h"
 #include "SkImageGenerator.h"
 #include "SkLazyPtr.h"
-#include "SkMutex.h"
 #include "SkTInternalLList.h"
+#include "SkThread.h"
 
 // Note:
 // A PoolDiscardableMemory is memory that is counted in a pool.
diff --git a/src/pathops/SkPathOpsDebug.cpp b/src/pathops/SkPathOpsDebug.cpp
index 643ff1d29f..627a7c9f40 100644
--- a/src/pathops/SkPathOpsDebug.cpp
+++ b/src/pathops/SkPathOpsDebug.cpp
@@ -5,10 +5,10 @@
  * found in the LICENSE file.
  */
 
-#include "SkMutex.h"
-#include "SkPath.h"
 #include "SkPathOpsDebug.h"
+#include "SkPath.h"
 #include "SkString.h"
+#include "SkThread.h"
 
 #if DEBUG_VALIDATE
 extern bool FLAGS_runFail;
@@ -304,7 +304,7 @@ SkString SkOpAngle::debugPart() const {
             break;
         default:
             SkASSERT(0);
-    }
+    } 
     return result;
 }
 #endif
diff --git a/src/ports/SkFontConfigInterface_direct.cpp b/src/ports/SkFontConfigInterface_direct.cpp
index 8589cc2421..239a7905ed 100644
--- a/src/ports/SkFontConfigInterface_direct.cpp
+++ b/src/ports/SkFontConfigInterface_direct.cpp
@@ -15,7 +15,6 @@
 #include "SkBuffer.h"
 #include "SkFontConfigInterface.h"
 #include "SkLazyPtr.h"
-#include "SkMutex.h"
 #include "SkStream.h"
 #include "SkString.h"
 
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 6f235edb8f..c0278317ff 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -17,12 +17,12 @@
 #include "SkMask.h"
 #include "SkMaskGamma.h"
 #include "SkMatrix22.h"
-#include "SkMutex.h"
 #include "SkOTUtils.h"
 #include "SkScalerContext.h"
 #include "SkStream.h"
 #include "SkString.h"
 #include "SkTemplates.h"
+#include "SkThread.h"
 #include "SkTypes.h"
 
 #if defined(SK_CAN_USE_DLOPEN)
diff --git a/src/ports/SkFontHost_FreeType_common.h b/src/ports/SkFontHost_FreeType_common.h
index a9ca42b35f..8ae872c1da 100644
--- a/src/ports/SkFontHost_FreeType_common.h
+++ b/src/ports/SkFontHost_FreeType_common.h
@@ -10,7 +10,6 @@
 #define SKFONTHOST_FREETYPE_COMMON_H_
 
 #include "SkGlyph.h"
-#include "SkMutex.h"
 #include "SkScalerContext.h"
 #include "SkTypeface.h"
 #include "SkTypes.h"
diff --git a/src/ports/SkFontHost_mac.cpp b/src/ports/SkFontHost_mac.cpp
index 5ad1c2fb5e..22e2954705 100755
--- a/src/ports/SkFontHost_mac.cpp
+++ b/src/ports/SkFontHost_mac.cpp
@@ -24,13 +24,12 @@
 #include "SkColorPriv.h"
 #include "SkDescriptor.h"
 #include "SkEndian.h"
-#include "SkFloatingPoint.h"
 #include "SkFontDescriptor.h"
-#include "SkFontMgr.h"
+#include "SkFloatingPoint.h"
 #include "SkGlyph.h"
 #include "SkLazyFnPtr.h"
 #include "SkMaskGamma.h"
-#include "SkMutex.h"
+#include "SkSFNTHeader.h"
 #include "SkOTTable_glyf.h"
 #include "SkOTTable_head.h"
 #include "SkOTTable_hhea.h"
@@ -38,12 +37,13 @@
 #include "SkOTUtils.h"
 #include "SkPaint.h"
 #include "SkPath.h"
-#include "SkSFNTHeader.h"
-#include "SkStream.h"
 #include "SkString.h"
-#include "SkTypefaceCache.h"
+#include "SkStream.h"
+#include "SkThread.h"
 #include "SkTypeface_mac.h"
 #include "SkUtils.h"
+#include "SkTypefaceCache.h"
+#include "SkFontMgr.h"
 #include "SkUtils.h"
 
 #include <dlfcn.h>
diff --git a/src/ports/SkFontHost_win.cpp b/src/ports/SkFontHost_win.cpp
index 7463dabee2..bcbbe11288 100755
--- a/src/ports/SkFontHost_win.cpp
+++ b/src/ports/SkFontHost_win.cpp
@@ -23,6 +23,7 @@
 #include "SkStream.h"
 #include "SkString.h"
 #include "SkTemplates.h"
+#include "SkThread.h"
 #include "SkTypeface_win.h"
 #include "SkTypefaceCache.h"
 #include "SkUtils.h"
diff --git a/src/ports/SkFontMgr_custom.cpp b/src/ports/SkFontMgr_custom.cpp
index cea0b4875e..49744a1f63 100644
--- a/src/ports/SkFontMgr_custom.cpp
+++ b/src/ports/SkFontMgr_custom.cpp
@@ -15,6 +15,7 @@
 #include "SkRTConf.h"
 #include "SkString.h"
 #include "SkStream.h"
+#include "SkThread.h"
 #include "SkTSearch.h"
 #include "SkTypefaceCache.h"
 #include "SkTArray.h"
diff --git a/src/ports/SkFontMgr_fontconfig.cpp b/src/ports/SkFontMgr_fontconfig.cpp
index 7000e31db4..c3cb26751e 100644
--- a/src/ports/SkFontMgr_fontconfig.cpp
+++ b/src/ports/SkFontMgr_fontconfig.cpp
@@ -11,10 +11,10 @@
 #include "SkFontMgr.h"
 #include "SkFontStyle.h"
 #include "SkMath.h"
-#include "SkMutex.h"
 #include "SkString.h"
 #include "SkStream.h"
 #include "SkTDArray.h"
+#include "SkThread.h"
 #include "SkTypefaceCache.h"
 #include "SkOSFile.h"
 
diff --git a/src/ports/SkFontMgr_win_dw.cpp b/src/ports/SkFontMgr_win_dw.cpp
index ca8b260580..b0cdf3c036 100644
--- a/src/ports/SkFontMgr_win_dw.cpp
+++ b/src/ports/SkFontMgr_win_dw.cpp
@@ -9,9 +9,9 @@
 #include "SkDWriteFontFileStream.h"
 #include "SkFontMgr.h"
 #include "SkHRESULT.h"
-#include "SkMutex.h"
 #include "SkStream.h"
 #include "SkTScopedComPtr.h"
+#include "SkThread.h"
 #include "SkTypeface.h"
 #include "SkTypefaceCache.h"
 #include "SkTypeface_win_dw.h"
diff --git a/src/ports/SkRemotableFontMgr_win_dw.cpp b/src/ports/SkRemotableFontMgr_win_dw.cpp
index 006346acab..d787a95374 100644
--- a/src/ports/SkRemotableFontMgr_win_dw.cpp
+++ b/src/ports/SkRemotableFontMgr_win_dw.cpp
@@ -5,15 +5,15 @@
  * found in the LICENSE file.
  */
 
+#include "SkDataTable.h"
 #include "SkDWrite.h"
 #include "SkDWriteFontFileStream.h"
-#include "SkDataTable.h"
 #include "SkHRESULT.h"
-#include "SkMutex.h"
 #include "SkRemotableFontMgr.h"
 #include "SkStream.h"
 #include "SkString.h"
 #include "SkTArray.h"
+#include "SkThread.h"
 #include "SkTScopedComPtr.h"
 #include "SkTypeface_win.h"
 #include "SkTypes.h"
@@ -80,7 +80,7 @@ private:
     }
 
 public:
-
+    
 
     /** localeNameLength must include the null terminator. */
     SkRemotableFontMgr_DirectWrite(IDWriteFontCollection* fontCollection,
diff --git a/src/ports/SkTLS_win.cpp b/src/ports/SkTLS_win.cpp
index c6f3dfc638..dea8cd4d6b 100644
--- a/src/ports/SkTLS_win.cpp
+++ b/src/ports/SkTLS_win.cpp
@@ -6,7 +6,7 @@
  */
 
 #include "SkTLS.h"
-#include "SkMutex.h"
+#include "SkThread.h"
 
 static bool gOnce = false;
 static DWORD gTlsIndex;
diff --git a/src/views/SkEvent.cpp b/src/views/SkEvent.cpp
index 5f204c0f0f..52a0c4dd7f 100644
--- a/src/views/SkEvent.cpp
+++ b/src/views/SkEvent.cpp
@@ -265,7 +265,7 @@ void SkEvent::inflate(const SkDOM& dom, const SkDOM::Node* node)
     #define EVENT_LOGN(s, n)
 #endif
 
-#include "SkMutex.h"
+#include "SkThread.h"
 #include "SkTime.h"
 
 class SkEvent_Globals {
diff --git a/src/views/SkEventSink.cpp b/src/views/SkEventSink.cpp
index 42c1ceb062..7763adef54 100644
--- a/src/views/SkEventSink.cpp
+++ b/src/views/SkEventSink.cpp
@@ -8,8 +8,10 @@
 
 
 #include "SkEventSink.h"
-#include "SkMutex.h"
 #include "SkTagList.h"
+#include "SkThread.h"
+
+#include "SkThread.h"
 #include "SkTime.h"
 
 class SkEventSink_Globals {
@@ -254,7 +256,7 @@ SkEventSink* SkEventSink::FindSink(SkEventSinkID sinkID)
 
 #if 0   // experimental, not tested
 
-#include "SkMutex.h"
+#include "SkThread.h"
 #include "SkTDict.h"
 
 #define kMinStringBufferSize    128
diff --git a/src/views/SkOSMenu.cpp b/src/views/SkOSMenu.cpp
index 8c2e47602f..ad0c73f80d 100644
--- a/src/views/SkOSMenu.cpp
+++ b/src/views/SkOSMenu.cpp
@@ -4,9 +4,9 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-#include "SkAtomics.h"
-#include "SkOSMenu.h"
 #include <stdarg.h>
+#include "SkOSMenu.h"
+#include "SkThread.h"
 
 static int gOSMenuCmd = 7000;
 
diff --git a/tests/AtomicTest.cpp b/tests/AtomicTest.cpp
index 7eb7a7103b..8b5ac9b679 100644
--- a/tests/AtomicTest.cpp
+++ b/tests/AtomicTest.cpp
@@ -5,7 +5,7 @@
  * found in the LICENSE file.
  */
 
-#include "SkAtomics.h"
+#include "SkThread.h"
 #include "SkThreadUtils.h"
 #include "SkTypes.h"
 #include "Test.h"
diff --git a/tests/PathOpsExtendedTest.cpp b/tests/PathOpsExtendedTest.cpp
index 69a2d617b0..df80f4673e 100644
--- a/tests/PathOpsExtendedTest.cpp
+++ b/tests/PathOpsExtendedTest.cpp
@@ -11,10 +11,10 @@
 #include "SkCanvas.h"
 #include "SkForceLinking.h"
 #include "SkMatrix.h"
-#include "SkMutex.h"
 #include "SkPaint.h"
 #include "SkRTConf.h"
 #include "SkStream.h"
+#include "SkThread.h"
 
 #ifdef SK_BUILD_FOR_MAC
 #include <sys/sysctl.h>
diff --git a/tests/PathOpsExtendedTest.h b/tests/PathOpsExtendedTest.h
index f8d74098ce..c4baa63b51 100644
--- a/tests/PathOpsExtendedTest.h
+++ b/tests/PathOpsExtendedTest.h
@@ -12,6 +12,8 @@
 #include "SkPath.h"
 #include "SkPathOpsTypes.h"
 #include "SkStream.h"
+#include "SkThread.h"
+#include "SkThreadUtils.h"
 #include "Test.h"
 
 DECLARE_bool(runFail);
diff --git a/tests/skia_test.cpp b/tests/skia_test.cpp
index 00043c1749..2c1822d38b 100644
--- a/tests/skia_test.cpp
+++ b/tests/skia_test.cpp
@@ -8,7 +8,6 @@
 #include "CrashHandler.h"
 #include "OverwriteLine.h"
 #include "Resources.h"
-#include "SkAtomics.h"
 #include "SkCommonFlags.h"
 #include "SkGraphics.h"
 #include "SkOSFile.h"
@@ -16,6 +15,7 @@
 #include "SkTArray.h"
 #include "SkTaskGroup.h"
 #include "SkTemplates.h"
+#include "SkThread.h"
 #include "SkTime.h"
 #include "Test.h"
 
diff --git a/tools/sk_tool_utils_font.cpp b/tools/sk_tool_utils_font.cpp
index 7b95fb04e0..925bd7dc76 100644
--- a/tools/sk_tool_utils_font.cpp
+++ b/tools/sk_tool_utils_font.cpp
@@ -7,9 +7,9 @@
 
 #include "Resources.h"
 #include "SkFontMgr.h"
-#include "SkMutex.h"
 #include "SkOSFile.h"
 #include "SkTestScalerContext.h"
+#include "SkThread.h"
 #include "SkUtils.h"
 #include "sk_tool_utils.h"
 
diff --git a/tools/skpdiff/SkDiffContext.h b/tools/skpdiff/SkDiffContext.h
index 9347d2651f..8f4789fea6 100644
--- a/tools/skpdiff/SkDiffContext.h
+++ b/tools/skpdiff/SkDiffContext.h
@@ -9,11 +9,11 @@
 #define SkDiffContext_DEFINED
 
 #include "SkImageDiffer.h"
-#include "SkMutex.h"
 #include "SkString.h"
 #include "SkTArray.h"
 #include "SkTDArray.h"
 #include "SkTLList.h"
+#include "SkThread.h"
 
 class SkWStream;
 
@@ -52,7 +52,7 @@ public:
     void setWhiteDiffDir(const SkString& directory);
 
     /**
-     * Modify the pattern used to generate commonName (= the
+     * Modify the pattern used to generate commonName (= the 
      * basename of rgb/white diff files).
      *
      * - true: basename is a combination of the input file names.
@@ -61,10 +61,10 @@ public:
      * For example, for:
      *   baselinePath=/tmp/dir/image-before.png
      *   testPath=/tmp/dir/image-after.png
-     *
+     * 
      * If setLongNames(true), commonName would be:
      *    image-before-png-vs-image-after-png.png
-     *
+     * 
      * If setLongNames(false), commonName would be:
      *   image-.png
      */
@@ -104,8 +104,8 @@ public:
      *
      * The format of the JSON document is one top level array named "records".
      * Each record in the array is an object with the following values:
-     *    "commonName"     : string containing the output filename (basename)
-     *                       depending on the value of 'longNames'.
+     *    "commonName"     : string containing the output filename (basename) 
+     *                       depending on the value of 'longNames'. 
      *                       (see 'setLongNames' for an explanation and example).
      *    "baselinePath"   : string containing the path to the baseline image
      *    "testPath"       : string containing the path to the test image