Fix the bug for VertexAttrib{I}Pointer when no array buffer bound

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 3c2f69440091f8020df96bec44979fa8f6892b18..d1eedc6ca86db1426307482880d6ebe9d7c81ce6 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -10909,10 +10909,13 @@ error::Error GLES2DecoderImpl::HandleVertexAttribIPointer(
       state_.bound_array_buffer->IsDeleted()) {
     if (state_.vertex_attrib_manager.get() ==
         state_.default_vertex_attrib_manager.get()) {
-      LOCAL_SET_GL_ERROR(
-          GL_INVALID_OPERATION,
-          "glVertexAttribIPointer", "no array buffer bound");
-      return error::kNoError;
+      if (offset != 0) {

[Zhenyao Mo, 2017/01/09 18:21:15]

I think you can combine this and the else to a simple (offset != 0) condition,
and the error message can just be "offset != 0".

[yunchao, 2017/01/10 14:10:11]

Done.

+        LOCAL_SET_GL_ERROR(
+            GL_INVALID_OPERATION,
+            "glVertexAttribIPointer",
+            "no array buffer is bound and offset is non-zero");
+        return error::kNoError;
+      }
     } else if (offset != 0) {
       LOCAL_SET_GL_ERROR(
           GL_INVALID_OPERATION,
@@ -11002,10 +11005,13 @@ error::Error GLES2DecoderImpl::HandleVertexAttribPointer(
       state_.bound_array_buffer->IsDeleted()) {
     if (state_.vertex_attrib_manager.get() ==
         state_.default_vertex_attrib_manager.get()) {
-      LOCAL_SET_GL_ERROR(
-          GL_INVALID_OPERATION,
-          "glVertexAttribPointer", "no array buffer bound");
-      return error::kNoError;
+      if (offset != 0) {

[Zhenyao Mo, 2017/01/09 18:21:15]

Same here.

[yunchao, 2017/01/10 14:10:11]

Done.

+        LOCAL_SET_GL_ERROR(
+            GL_INVALID_OPERATION,
+            "glVertexAttribPointer",
+            "no array buffer is bound and offset is non-zero");
+        return error::kNoError;
+      }
     } else if (offset != 0) {
       LOCAL_SET_GL_ERROR(
           GL_INVALID_OPERATION,