Build SkThreadUtils (home of SkThread type) too.

skia/skia_library.gypi

Index: skia/skia_library.gypi
diff --git a/skia/skia_library.gypi b/skia/skia_library.gypi
index 88fa22248a5aac3ce8dc77802fc00ef8d11d6569..6879cfc5324943a82c754825eb2cca54141535a1 100644
--- a/skia/skia_library.gypi
+++ b/skia/skia_library.gypi
@@ -132,17 +132,13 @@
   '../third_party/skia/src/utils/SkPathUtils.cpp',
   '../third_party/skia/src/utils/SkSHA1.cpp',
   '../third_party/skia/src/utils/SkSHA1.h',
-  '../third_party/skia/src/utils/SkThreadUtils.h',
-  '../third_party/skia/src/utils/SkThreadUtils_pthread.cpp',
-  '../third_party/skia/src/utils/SkThreadUtils_pthread.h',
-  '../third_party/skia/src/utils/SkThreadUtils_pthread_linux.cpp',
-  '../third_party/skia/src/utils/SkThreadUtils_pthread_mach.cpp',
-  '../third_party/skia/src/utils/SkThreadUtils_pthread_other.cpp',
-  '../third_party/skia/src/utils/SkThreadUtils_win.cpp',
-  '../third_party/skia/src/utils/SkThreadUtils_win.h',
   '../third_party/skia/src/utils/SkTFitsIn.h',
   '../third_party/skia/src/utils/SkTLogic.h',
 
+  # We don't currently need to change thread affinity, so leave out this complexity for now.
+  "../third_party/skia/src/utils/SkThreadUtils_pthread_mach.cpp",
+  "../third_party/skia/src/utils/SkThreadUtils_pthread_linux.cpp",
+
 #windows
   '../third_party/skia/include/utils/win/SkAutoCoInitialize.h',
   '../third_party/skia/include/utils/win/SkHRESULT.h',
@@ -202,6 +198,19 @@
       ],
     }],
 
+    [ 'OS == "win"', {
+      'sources!': [
+        # Keeping _win.cpp
+        "../third_party/skia/src/utils/SkThreadUtils_pthread.cpp",
+        "../third_party/skia/src/utils/SkThreadUtils_pthread_other.cpp",
+      ],
+    },{
+      'sources!': [
+        # Keeping _pthread.cpp and _pthread_other.cpp
+        "../third_party/skia/src/utils/SkThreadUtils_win.cpp",
+      ],
+    }],
+
     [ 'OS != "mac"', {
       'sources/': [
         ['exclude', '/mac/']