Minor tweaks to API documentation and code comments.

mojo/public/c/system/types.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains types and constants/macros common to different Mojo system
 // APIs.
 //
 // Note: This header should be compilable as C.
 
 #ifndef MOJO_PUBLIC_C_SYSTEM_TYPES_H_
 #define MOJO_PUBLIC_C_SYSTEM_TYPES_H_
 
 #include <stdint.h>
 
 #include "mojo/public/c/system/macros.h"
 
 // TODO(vtl): Notes: Use of undefined flags will lead to undefined behavior
 // (typically they'll be ignored), not necessarily an error.
 
-// |MojoTimeTicks|: Used to specify time ticks. Value is in microseconds.
+// |MojoTimeTicks|: A time delta, in microseconds, the meaning of which is
+// source-dependent.
 
 typedef int64_t MojoTimeTicks;
 
 // |MojoHandle|: Handles to Mojo objects.
 //   |MOJO_HANDLE_INVALID| - A value that is never a valid handle.
 
 typedef uint32_t MojoHandle;
 
 #ifdef __cplusplus
 const MojoHandle MOJO_HANDLE_INVALID = 0;
@@ skipping 146 matching lines @@
 // 32-bit-aligned.
 MOJO_STATIC_ASSERT(MOJO_ALIGNOF(int32_t) == 4, "int32_t has weird alignment");
 struct MOJO_ALIGNAS(4) MojoHandleSignalsState {
   MojoHandleSignals satisfied_signals;
   MojoHandleSignals satisfiable_signals;
 };
 MOJO_STATIC_ASSERT(sizeof(MojoHandleSignalsState) == 8,
                    "MojoHandleSignalsState has wrong size");
 
 #endif  // MOJO_PUBLIC_C_SYSTEM_TYPES_H_