Add extra safety check to the EGL context setup.

src/gpu/gl/egl/SkCreatePlatformGLContext_egl.cpp

 
 /*
  * 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/SkGLContext.h"
 
 #include <GLES2/gl2.h>
@@ skipping 69 matching lines @@
         SkDebugf("VENDOR: %s\n", eglQueryString(fDisplay, EGL_VENDOR));
         SkDebugf("APIS: %s\n", eglQueryString(fDisplay, EGL_CLIENT_APIS));
         SkDebugf("VERSION: %s\n", eglQueryString(fDisplay, EGL_VERSION));
         SkDebugf("EXTENSIONS %s\n", eglQueryString(fDisplay, EGL_EXTENSIONS));
 #endif
 
         if (!eglBindAPI(kAPIs[api].fAPI)) {
             continue;
         }
 
-        EGLint numConfigs;
+        EGLint numConfigs = 0;
         const EGLint configAttribs[] = {
             EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
             EGL_RENDERABLE_TYPE, kAPIs[api].fRenderableTypeBit,
             EGL_RED_SIZE, 8,
             EGL_GREEN_SIZE, 8,
             EGL_BLUE_SIZE, 8,
             EGL_ALPHA_SIZE, 8,
             EGL_NONE
         };
 
         EGLConfig surfaceConfig;
         if (!eglChooseConfig(fDisplay, configAttribs, &surfaceConfig, 1, &numConfigs)) {
             SkDebugf("eglChooseConfig failed. EGL Error: 0x%08x\n", eglGetError());
             continue;
         }
 
+        if (0 == numConfigs) {
+            SkDebugf("No suitable EGL config found.\n");
+            continue;
+        }
+
         fContext = eglCreateContext(fDisplay, surfaceConfig, NULL, kAPIs[api].fContextAttribs);
         if (EGL_NO_CONTEXT == fContext) {
             SkDebugf("eglCreateContext failed.  EGL Error: 0x%08x\n", eglGetError());
             continue;
         }
 
         static const EGLint kSurfaceAttribs[] = {
             EGL_WIDTH, 1,
             EGL_HEIGHT, 1,
             EGL_NONE
@@ skipping 68 matching lines @@
 
 SkGLContext* SkCreatePlatformGLContext(GrGLStandard forcedGpuAPI) {
     EGLGLContext* ctx = SkNEW_ARGS(EGLGLContext, (forcedGpuAPI));
     if (!ctx->isValid()) {
         SkDELETE(ctx);
         return NULL;
     }
     return ctx;
 }