WebGL 2: make sure VertexAttrib type match the corresponding attrib type in shader

gpu/command_buffer/service/vertex_attrib_manager.h

Index: gpu/command_buffer/service/vertex_attrib_manager.h
diff --git a/gpu/command_buffer/service/vertex_attrib_manager.h b/gpu/command_buffer/service/vertex_attrib_manager.h
index f3fae6d2d8f2e98ab144da10dad5f1ba210cfe1a..42ede30ebcf9a5b52bda4e0f8538d3d39272549d 100644
--- a/gpu/command_buffer/service/vertex_attrib_manager.h
+++ b/gpu/command_buffer/service/vertex_attrib_manager.h
@@ -200,6 +200,22 @@ class GPU_EXPORT VertexAttribManager :
     return NULL;
   }
 
+  void UpdateAttribBaseTypeAndMask(GLuint loc, GLenum base_type) {
+    DCHECK(loc >=0 && loc < 16);
+    int shift_bits = loc * 2;
+    attrib_written_mask_ |= 0x3 << shift_bits;
+    attrib_base_type_mask_ &= ~(0x3 << shift_bits);
+    attrib_base_type_mask_ |= base_type << shift_bits;
+  }
+
+  uint32_t attrib_base_type_mask() const {
+      return attrib_base_type_mask_;
+  }
+
+  uint32_t attrib_written_mask() const {
+      return attrib_written_mask_;
+  }
+
   void SetAttribInfo(
       GLuint index,
       Buffer* buffer,
@@ -284,6 +300,14 @@ class GPU_EXPORT VertexAttribManager :
   // if it is safe to draw.
   std::vector<VertexAttrib> vertex_attribs_;
 
+  // Vertex attrib base types: FLOAT, INT, or UINT.
+  // We have up to 16 attribs, each is encoded into 2 bits, total 32 bits:
+  // the lowest 2 bits for location 0, the highest 2 bits for location 15.
+  uint32_t attrib_base_type_mask_;
+  // Same layout as above, 2 bits per location, 0x03 if a location is set
+  // by vertexAttrib API, 0x00 if not.
+  uint32_t attrib_written_mask_;
+
   // The currently bound element array buffer. If this is 0 it is illegal
   // to call glDrawElements.
   scoped_refptr<Buffer> element_array_buffer_;