Change by-ref passed float or bool parameters to callbacks in public API

* Mostly used for passing a progress float back during a long blocking
  call like opening a capture or doing a copy.
* This is much more feasible for python to bind to.
* In several cases we just use a tiny lambda that updates a float anyway
  since we can't push the progress directly into a progress dialog, but
  need to let it query from a temporary in-between float.

renderdoc/serialise/codecs/chrome_json_codec.cpp

@@ -27,7 +27,7 @@
 #include "serialise/rdcfile.h"
 
 ReplayStatus exportChrome(const char *filename, const RDCFile &rdc, const SDFile &structData,
-                          float *progress)
+                          RENDERDOC_ProgressCallback progress)
 {
   FILE *f = FileIO::fopen(filename, "w");
 
@@ -46,6 +46,9 @@ ReplayStatus exportChrome(const char *filename, const RDCFile &rdc, const SDFile
   // stupid JSON not allowing trailing ,s :(
   bool first = true;
 
+  int i = 0;
+  int numChunks = structData.chunks.count();
+
   for(const SDChunk *chunk : structData.chunks)
   {
     if(chunk->metadata.chunkID == (uint32_t)SystemChunk::FirstDriverChunk + 1)
@@ -69,8 +72,16 @@ ReplayStatus exportChrome(const char *filename, const RDCFile &rdc, const SDFile
     str += StringFormat::Fmt(
         fmt, chunk->name.c_str(), category, chunk->metadata.timestampMicro, chunk->metadata.threadID,
         chunk->metadata.timestampMicro + chunk->metadata.durationMicro, chunk->metadata.threadID);
+
+    if(progress)
+      progress(float(i) / float(numChunks));
+
+    i++;
   }
 
+  if(progress)
+    progress(1.0f);
+
   // end trace events
   str += "\n  ]\n}";