Implement basic query functionality in the passthrough command buffer.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
index 6c3a5bdc37440d15795ece11cbfa8e58cbfb17ad..d9a47aacaad6b9ab2ab6c7b3a1da67c28e57efcd 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h
@@ -241,6 +241,13 @@ class GLES2DecoderPassthroughImpl : public GLES2Decoder {
  private:
   void BuildExtensionsString();
 
+  void InsertError(GLenum error, const std::string& message);
+  GLenum PopError();
+  bool FlushErrors();
+
+  bool IsEmulatedQueryTarget(GLenum target) const;
+  error::Error ProcessQueries(bool did_finish);
+
   int commands_to_process_;
 
   DebugMarkerManager debug_marker_manager_;
@@ -303,6 +310,33 @@ class GLES2DecoderPassthroughImpl : public GLES2Decoder {
   size_t active_texture_unit_;
   std::vector<GLuint> bound_textures_;
 
+  // Track the service-id to type of all queries for validation
+  struct QueryInfo {
+    GLenum type = GL_NONE;
+  };
+  std::unordered_map<GLuint, QueryInfo> query_info_map_;

[piman, 2016/11/18 19:32:09]

nit: any reason to use the service id to index here? If using the client ids I
think it would save a few map lookups.

[Geoff Lang, 2016/11/21 18:12:16]

I found it needed the same number of lookups because the service ID was always
needed at the same time.  I'd like to merge the two maps though, no technical
reason why the service id and and query type can't be stored in the same struct
but the ClientServiceMap class can't handle that yet.  

+
+  // All queries that are waiting for their results to be ready
+  struct PendingQuery {
+    GLenum target = GL_NONE;
+    GLuint service_id = 0;
+
+    int32_t shm_id = 0;
+    uint32_t shm_offset = 0;
+    base::subtle::Atomic32 submit_count = 0;
+  };
+  std::deque<PendingQuery> pending_queries_;
+
+  // Currently active queries
+  struct ActiveQuery {
+    GLuint service_id = 0;
+    int32_t shm_id = 0;
+    uint32_t shm_offset = 0;
+  };
+  std::unordered_map<GLenum, ActiveQuery> active_queries_;
+
+  std::set<GLenum> errors_;
+
   std::vector<std::string> emulated_extensions_;
   std::string extension_string_;