libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/utils/thread.h

Index: third_party/libwebp/utils/thread.h
diff --git a/third_party/libwebp/utils/thread.h b/third_party/libwebp/utils/thread.h
index 3191890b7686d119b3254265a097f75a6b832c28..9afe09679f766d6c18ce7004c4bf9474a82f172a 100644
--- a/third_party/libwebp/utils/thread.h
+++ b/third_party/libwebp/utils/thread.h
@@ -12,6 +12,10 @@
 #ifndef WEBP_UTILS_THREAD_H_
 #define WEBP_UTILS_THREAD_H_
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif
@@ -63,13 +67,13 @@ typedef struct {
 
 // Must be called first, before any other method.
 void WebPWorkerInit(WebPWorker* const worker);
-// Must be called initialize the object and spawn the thread. Re-entrant.
+// Must be called to initialize the object and spawn the thread. Re-entrant.
 // Will potentially launch the thread. Returns false in case of error.
 int WebPWorkerReset(WebPWorker* const worker);
-// Make sure the previous work is finished. Returns true if worker->had_error
-// was not set and not error condition was triggered by the working thread.
+// Makes sure the previous work is finished. Returns true if worker->had_error
+// was not set and no error condition was triggered by the working thread.
 int WebPWorkerSync(WebPWorker* const worker);
-// Trigger the thread to call hook() with data1 and data2 argument. These
+// Triggers the thread to call hook() with data1 and data2 argument. These
 // hook/data1/data2 can be changed at any time before calling this function,
 // but not be changed afterward until the next call to WebPWorkerSync().
 void WebPWorkerLaunch(WebPWorker* const worker);