Disable IOSurface clearing on OS X 10.9.

ui/gl/test/gl_image_test_template.h

Index: ui/gl/test/gl_image_test_template.h
diff --git a/ui/gl/test/gl_image_test_template.h b/ui/gl/test/gl_image_test_template.h
index 28567bc2e2e0fb5500eb3c0782dd85ceab0978a3..e10c64c77396624d3dda5c5e1faa97e01c202787 100644
--- a/ui/gl/test/gl_image_test_template.h
+++ b/ui/gl/test/gl_image_test_template.h
@@ -13,6 +13,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/stringize_macros.h"
 #include "base/strings/stringprintf.h"
+#include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/buffer_format_util.h"
 #include "ui/gfx/buffer_types.h"
@@ -25,6 +26,10 @@
 #include "ui/gl/test/gl_image_test_support.h"
 #include "ui/gl/test/gl_test_helper.h"
 
+#if defined(OS_MACOSX)
+#include "base/mac/mac_util.h"
+#endif
+
 namespace gl {
 namespace {
 
@@ -178,6 +183,13 @@ class GLImageZeroInitializeTest : public GLImageTest<GLImageTestDelegate> {};
 TYPED_TEST_CASE_P(GLImageZeroInitializeTest);
 
 TYPED_TEST_P(GLImageZeroInitializeTest, ZeroInitialize) {
+#if defined(OS_MACOSX)
+  // This functionality is disabled on Mavericks because it breaks PDF
+  // rendering. https://crbug.com/594343.
+  if (base::mac::IsOSMavericks())
+    return;
+#endif
+
   const gfx::Size image_size(256, 256);
 
   GLuint framebuffer =