command_buffer: Implement path rendering functions for CHROMIUM_path_rendering

gpu/command_buffer/common/id_allocator.h

Index: gpu/command_buffer/common/id_allocator.h
diff --git a/gpu/command_buffer/common/id_allocator.h b/gpu/command_buffer/common/id_allocator.h
index b877083008ad724f515799283d66173215d03344..7f83a9c6691caefb911d15f4387c7619f127cd9a 100644
--- a/gpu/command_buffer/common/id_allocator.h
+++ b/gpu/command_buffer/common/id_allocator.h
@@ -36,12 +36,20 @@ class GPU_EXPORT IdAllocator {
   // Note: may wrap if it starts near limit.
   ResourceId AllocateIDAtOrAbove(ResourceId desired_id);
 
+  // Allocates |range| amount of contiguous ids.
+  // Returns the first id to |first_id| or |kInvalidResource| if
+  // allocation failed.
+  ResourceId AllocateIDRange(uint32_t range);
+
   // Marks an id as used. Returns false if id was already used.
   bool MarkAsUsed(ResourceId id);
 
   // Frees a resource ID.
   void FreeID(ResourceId id);
 
+  // Frees a |range| amount of contiguous ids, starting from |first_id|.
+  void FreeIDRange(ResourceId first_id, uint32_t range);
+
   // Checks whether or not a resource ID is in use.
   bool InUse(ResourceId id) const;