Revert of Make the Sk GL context class an abstract base class

src/gpu/gl/mac/SkNativeGLContext_mac.cpp

Index: src/gpu/gl/mac/SkNativeGLContext_mac.cpp
diff --git a/src/gpu/gl/mac/SkNativeGLContext_mac.cpp b/src/gpu/gl/mac/SkNativeGLContext_mac.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f63471c16a38275606103ed92ebd7b80fad73670
--- /dev/null
+++ b/src/gpu/gl/mac/SkNativeGLContext_mac.cpp
@@ -0,0 +1,84 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "gl/SkNativeGLContext.h"
+#include "AvailabilityMacros.h"
+
+SkNativeGLContext::AutoContextRestore::AutoContextRestore() {
+    fOldCGLContext = CGLGetCurrentContext();
+}
+
+SkNativeGLContext::AutoContextRestore::~AutoContextRestore() {
+    CGLSetCurrentContext(fOldCGLContext);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkNativeGLContext::SkNativeGLContext()
+    : fContext(NULL) {
+}
+
+SkNativeGLContext::~SkNativeGLContext() {
+    this->destroyGLContext();
+}
+
+void SkNativeGLContext::destroyGLContext() {
+    if (fContext) {
+        CGLReleaseContext(fContext);
+    }
+}
+
+const GrGLInterface* SkNativeGLContext::createGLContext(GrGLStandard forcedGpuAPI) {
+    SkASSERT(NULL == fContext);
+    if (kGLES_GrGLStandard == forcedGpuAPI) {
+        return NULL;
+    }
+
+    CGLPixelFormatAttribute attributes[] = {
+#if MAC_OS_X_VERSION_10_7
+        kCGLPFAOpenGLProfile, (CGLPixelFormatAttribute) kCGLOGLPVersion_3_2_Core,
+#endif
+        kCGLPFADoubleBuffer,
+        (CGLPixelFormatAttribute)0
+    };
+    CGLPixelFormatObj pixFormat;
+    GLint npix;
+
+    CGLChoosePixelFormat(attributes, &pixFormat, &npix);
+
+    if (NULL == pixFormat) {
+        SkDebugf("CGLChoosePixelFormat failed.");
+        return NULL;
+    }
+
+    CGLCreateContext(pixFormat, NULL, &fContext);
+    CGLReleasePixelFormat(pixFormat);
+
+    if (NULL == fContext) {
+        SkDebugf("CGLCreateContext failed.");
+        return NULL;
+    }
+
+    CGLSetCurrentContext(fContext);
+
+    const GrGLInterface* interface = GrGLCreateNativeInterface();
+    if (NULL == interface) {
+        SkDebugf("Context could not create GL interface.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    return interface;
+}
+
+void SkNativeGLContext::makeCurrent() const {
+    CGLSetCurrentContext(fContext);
+}
+
+void SkNativeGLContext::swapBuffers() const {
+    CGLFlushDrawable(fContext);
+}