Don't require -DSK_USE_POSIX_THREADS.

To compile SkCondVar, we already require either pthreads or Windows.  This
simplifies that code to not need SK_USE_POSIX_THREADS to be explicitly defined.
We'll just look to see if we're targeting Windows, and if not, assume pthreads.

Both before and after this CL, that code will fail to compile if we're not on
Windows and don't have pthreads.

BUG=skia:

Review URL: https://codereview.chromium.org/869443003

gyp/common_conditions.gypi

@@ -632,14 +632,6 @@
       },
     ],
 
-    # We can POD-style initialization of static mutexes to avoid generating
-    # static initializers if we're using a pthread-compatible thread interface.
-    [ 'skia_os != "win"', {
-      'defines': [
-        'SK_USE_POSIX_THREADS',
-      ],
-    }],
-
     [ 'skia_moz2d', {
       'defines': [
         # add flags here (e.g. SK_SUPPORT_LEGACY_...) needed by moz2d

src/core/SkPixelRef.cpp

@@ -8,8 +8,14 @@
 #include "SkPixelRef.h"
 #include "SkThread.h"
 
-#ifdef SK_USE_POSIX_THREADS
+#ifdef SK_BUILD_FOR_WIN32
+    // We don't have SK_BASE_MUTEX_INIT on Windows.
 
+    // must be a power-of-2. undef to just use 1 mutex
+    #define PIXELREF_MUTEX_RING_COUNT       32
+    static SkBaseMutex gPixelRefMutexRing[PIXELREF_MUTEX_RING_COUNT];
+
+#else
     static SkBaseMutex gPixelRefMutexRing[] = {
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
@@ -31,16 +37,9 @@
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
         SK_BASE_MUTEX_INIT, SK_BASE_MUTEX_INIT,
     };
-
     // must be a power-of-2. undef to just use 1 mutex
     #define PIXELREF_MUTEX_RING_COUNT SK_ARRAY_COUNT(gPixelRefMutexRing)
 
-#else // not pthreads
-
-    // must be a power-of-2. undef to just use 1 mutex
-    #define PIXELREF_MUTEX_RING_COUNT       32
-    static SkBaseMutex gPixelRefMutexRing[PIXELREF_MUTEX_RING_COUNT];
-
 #endif
 
 static SkBaseMutex* get_default_mutex() {

src/utils/SkCondVar.cpp

@@ -18,9 +18,7 @@
 #endif
 
 bool SkCondVar::Supported() {
-#ifdef SK_USE_POSIX_THREADS
-    return true;
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     // If we're >= Vista we'll find these functions.  Otherwise (XP) SkCondVar is not supported.
     HMODULE kernel32 = GetModuleHandleA("kernel32.dll");
     set_fn_ptr(&initialize_condition_variable,
@@ -36,70 +34,70 @@ bool SkCondVar::Supported() {
         && wake_condition_variable
         && wake_all_condition_variable;
 #else
-    return false;
+    return true;
 #endif
 }
 
 SkCondVar::SkCondVar() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_mutex_init(&fMutex, NULL /* default mutex attr */);
-    pthread_cond_init(&fCond, NULL /* default cond attr */);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     InitializeCriticalSection(&fCriticalSection);
     SkASSERT(initialize_condition_variable);
     initialize_condition_variable(&fCondition);
+#else
+    pthread_mutex_init(&fMutex, NULL /* default mutex attr */);
+    pthread_cond_init(&fCond, NULL /* default cond attr */);
 #endif
 }
 
 SkCondVar::~SkCondVar() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_mutex_destroy(&fMutex);
-    pthread_cond_destroy(&fCond);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     DeleteCriticalSection(&fCriticalSection);
     // No need to clean up fCondition.
+#else
+    pthread_mutex_destroy(&fMutex);
+    pthread_cond_destroy(&fCond);
 #endif
 }
 
 void SkCondVar::lock() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_mutex_lock(&fMutex);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     EnterCriticalSection(&fCriticalSection);
+#else
+    pthread_mutex_lock(&fMutex);
 #endif
 }
 
 void SkCondVar::unlock() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_mutex_unlock(&fMutex);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     LeaveCriticalSection(&fCriticalSection);
+#else
+    pthread_mutex_unlock(&fMutex);
 #endif
 }
 
 void SkCondVar::wait() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_cond_wait(&fCond, &fMutex);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     SkASSERT(sleep_condition_variable);
     sleep_condition_variable(&fCondition, &fCriticalSection, INFINITE);
+#else
+    pthread_cond_wait(&fCond, &fMutex);
 #endif
 }
 
 void SkCondVar::signal() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_cond_signal(&fCond);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     SkASSERT(wake_condition_variable);
     wake_condition_variable(&fCondition);
+#else
+    pthread_cond_signal(&fCond);
 #endif
 }
 
 void SkCondVar::broadcast() {
-#ifdef SK_USE_POSIX_THREADS
-    pthread_cond_broadcast(&fCond);
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     SkASSERT(wake_all_condition_variable);
     wake_all_condition_variable(&fCondition);
+#else
+    pthread_cond_broadcast(&fCond);
 #endif
 }

src/utils/SkCondVar.h

@@ -10,12 +10,10 @@
 
 #include "SkTypes.h"
 
-#ifdef SK_USE_POSIX_THREADS
-    #include <pthread.h>
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     #include <windows.h>
 #else
-    #error "SkCondVar requires pthreads or Windows."
+    #include <pthread.h>
 #endif
 
 /**
@@ -64,12 +62,12 @@ class SkCondVar {
     void broadcast();
 
 private:
-#ifdef SK_USE_POSIX_THREADS
-    pthread_mutex_t  fMutex;
-    pthread_cond_t   fCond;
-#elif defined(SK_BUILD_FOR_WIN32)
+#ifdef SK_BUILD_FOR_WIN32
     CRITICAL_SECTION   fCriticalSection;
     CONDITION_VARIABLE fCondition;
+#else
+    pthread_mutex_t  fMutex;
+    pthread_cond_t   fCond;
 #endif
 };