Remove reliance on linked in GL functions for assembling GLES interfaces

src/gpu/gl/iOS/SkNativeGLContext_iOS.mm

 
 /*
  * 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 "gl/SkNativeGLContext.h"
 #import <OpenGLES/EAGL.h>
@@ skipping 18 matching lines @@
 
 SkNativeGLContext::SkNativeGLContext()
     : fEAGLContext(NULL) {
 }
 
 SkNativeGLContext::~SkNativeGLContext() {
     this->destroyGLContext();
 }
 
 void SkNativeGLContext::destroyGLContext() {
-    if ([EAGLContext currentContext] == EAGLCTX) {
-        [EAGLContext setCurrentContext:nil];
+    if (NULL != fEAGLContext) {
+        if ([EAGLContext currentContext] == EAGLCTX) {
+            [EAGLContext setCurrentContext:nil];
+        }
+        [EAGLCTX release];
+        fEAGLContext = NULL;
     }
-    [EAGLCTX release];
 }
 
 const GrGLInterface* SkNativeGLContext::createGLContext(GrGLStandard forcedGpuAPI) {
     if (kGL_GrGLStandard == forcedGpuAPI) {
         return NULL;
     }
 
     fEAGLContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
     [EAGLContext setCurrentContext:EAGLCTX];
     
     const GrGLInterface* interface = GrGLCreateNativeInterface();
     if (!interface) {
         SkDebugf("Failed to create gl interface");
         this->destroyGLContext();
         return NULL;
     }
     return interface;
 }
 
 void SkNativeGLContext::makeCurrent() const {
     if (![EAGLContext setCurrentContext:EAGLCTX]) {
         SkDebugf("Could not set the context.\n");
     }
 }
 
 void SkNativeGLContext::swapBuffers() const { }