New default vertex attribute size

VertexAttribute objects should have a default size of 4.

Fixes dEQP-GLES3.functional.state_query.shader.vertex_attrib_size

Change-Id: I597d2095f7be087f35a4adfb01bb2a3ba5200701
Reviewed-on: https://swiftshader-review.googlesource.com/14928
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/OpenGL/libGLESv2/Context.h b/src/OpenGL/libGLESv2/Context.h
index 27147a5..a7d2773 100644
--- a/src/OpenGL/libGLESv2/Context.h
+++ b/src/OpenGL/libGLESv2/Context.h
@@ -194,7 +194,7 @@
 class VertexAttribute
 {
 public:
-	VertexAttribute() : mType(GL_FLOAT), mSize(0), mNormalized(false), mStride(0), mDivisor(0), mPointer(nullptr), mArrayEnabled(false)
+	VertexAttribute() : mType(GL_FLOAT), mSize(4), mNormalized(false), mStride(0), mDivisor(0), mPointer(nullptr), mArrayEnabled(false)
 	{
 		mCurrentValue[0].f = 0.0f;
 		mCurrentValue[1].f = 0.0f;