Command buffer: Fix bugs for drawing when the type of vertex attrib is a packed type

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 ae331e5a4a080d4cf275e8cb35d2caf30011a28a..67d05245a7d89848f35afc32c5d382300fa8b2f0 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -8919,15 +8919,19 @@ error::Error GLES2DecoderImpl::HandleVertexAttribPointer(
   }
   GLsizei component_size =
       GLES2Util::GetGLTypeSizeForTexturesAndBuffers(type);
-  // component_size must be a power of two to use & as optimized modulo.
-  DCHECK(GLES2Util::IsPOT(component_size));
-  if (offset & (component_size - 1)) {
+  GLsizei data_size = component_size;
+  if (type == GL_INT_2_10_10_10_REV || type == GL_UNSIGNED_INT_2_10_10_10_REV) {
+    data_size = component_size * size;
+  }
+  // data_size must be a power of two to use & as optimized modulo.
+  DCHECK(GLES2Util::IsPOT(data_size));
+  if (offset & (data_size - 1)) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,
         "glVertexAttribPointer", "offset not valid for type");
     return error::kNoError;
   }
-  if (stride & (component_size - 1)) {
+  if (stride & (data_size - 1)) {

[yunchao, 2016/02/18 14:55:30]

The offset and stride should be aligned with the element_size (component_size *
component_count) for packed types(INT_2_10_10_10_REV and
UNSIGNED_2_10_10_10_REV).

     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,
         "glVertexAttribPointer", "stride not valid for type");