fix build for linux
partial impl for GPU on linux (need getProcAddress and SkEGLContext)



git-svn-id: http://skia.googlecode.com/svn/trunk@661 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 17ed8e4..e406c79 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -218,9 +218,11 @@
 	}
 
     // setup a GL context for drawing offscreen
+    GrContext* context = NULL;
     SkEGLContext eglContext;
-    eglContext.init(1024, 1024);
-    GrContext* context = GrContext::CreateGLShaderContext();
+    if (eglContext.init(1024, 1024)) {
+        context = GrContext::CreateGLShaderContext();
+    }
 
     Iter iter;
     GM* gm;
@@ -244,6 +246,9 @@
 			SkCanvas canvas(bitmap);
 
             if (gRec[i].fUseGPU) {
+                if (NULL == context) {
+                    continue;
+                }
                 SkGpuCanvas gc(context);
                 gc.setDevice(gc.createDevice(bitmap.config(), bitmap.width(), bitmap.height(),
                                              bitmap.isOpaque(), false))->unref();