Implement GLHelperReadbackSupport for GLHelper usage.

content/common/gpu/client/gl_helper_unittest.cc

Index: content/common/gpu/client/gl_helper_unittest.cc
diff --git a/content/common/gpu/client/gl_helper_unittest.cc b/content/common/gpu/client/gl_helper_unittest.cc
index 91cfa2179f5261cb855609e567c514b9ed93d9bf..1cb10590188d109f953b35b1ef04cf9dfa6206e6 100644
--- a/content/common/gpu/client/gl_helper_unittest.cc
+++ b/content/common/gpu/client/gl_helper_unittest.cc
@@ -1001,12 +1001,9 @@ class GLHelperTest : public testing::Test {
   bool TestTextureFormatReadback(const gfx::Size& src_size,
                          SkBitmap::Config bitmap_config,
                          bool async) {
-    DCHECK((bitmap_config == SkBitmap::kRGB_565_Config) ||
-           (bitmap_config == SkBitmap::kARGB_8888_Config));
-    bool rgb565_format = (bitmap_config == SkBitmap::kRGB_565_Config);
-    if (rgb565_format && !helper_->CanUseRgb565Readback()) {
-      LOG(INFO) << "RGB565 Format Not supported on this platform";
-      LOG(INFO) << "Skipping RGB565ReadBackTest";
+    if (!helper_->IsReadBackConfigSupported(bitmap_config)) {
+      LOG(INFO) << "Format Not supported on this platform" << bitmap_config
+                << "Skipping the test";

[no sievers, 2014/02/19 19:09:39]

nit: does this need to be spaced? something like
 LOG(INFO) << "Format Not supported on this platform: " << bitmap_config << ".
Skipping the test";

[sivag, 2014/02/21 11:40:51]

Done.

       return true;
     }
     WebGLId src_texture = context_->createTexture();