Replace Error(GL_NO_ERROR) with NoError().

In order to make the errors be consistent throughout ANGLE.

BUG=angleproject:1686

Change-Id: I0a2d86091d640aedeac94beae345c1fb6971b00d
Reviewed-on: https://chromium-review.googlesource.com/424835
Commit-Queue: Yunchao He <yunchao.he@intel.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/gl/RendererGL.cpp b/src/libANGLE/renderer/gl/RendererGL.cpp
index 1e6c519..7865ee2 100644
--- a/src/libANGLE/renderer/gl/RendererGL.cpp
+++ b/src/libANGLE/renderer/gl/RendererGL.cpp
@@ -160,7 +160,7 @@
 gl::Error RendererGL::flush()
 {
     mFunctions->flush();
-    return gl::Error(GL_NO_ERROR);
+    return gl::NoError();
 }
 
 gl::Error RendererGL::finish()
@@ -181,7 +181,7 @@
     }
 #endif
 
-    return gl::Error(GL_NO_ERROR);
+    return gl::NoError();
 }
 
 gl::Error RendererGL::drawArrays(const gl::ContextState &data,
@@ -271,7 +271,7 @@
         mFunctions->drawRangeElements(mode, start, end, count, type, drawIndexPointer);
     }
 
-    return gl::Error(GL_NO_ERROR);
+    return gl::NoError();
 }
 
 gl::Error RendererGL::drawArraysIndirect(const gl::ContextState &data,