Add GL_EXT_color_buffer_half_float support

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 20945540784af870e841cec7cc708996364183e8..9c9500cb97c72a92d3ba7d462f28fac0d9ad3917 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -547,7 +547,7 @@ bool ResourceProvider::IsResourceFormatSupported(ResourceFormat format) const {
       // TODO(ccameron): This will always return false on pixel tests, which
       // makes it un-test-able until we upgrade Mesa.
       // https://crbug.com/687720
-      return caps.texture_half_float_linear && caps.color_buffer_float;
+      return caps.texture_half_float_linear && caps.color_buffer_half_float;
   }
 
   NOTREACHED();