rewrite includes to not need so much -Ifoo

Current strategy: everything from the top

Things to look at first are the manual changes:

   - added tools/rewrite_includes.py
   - removed -Idirectives from BUILD.gn
   - various compile.sh simplifications
   - tweak tools/embed_resources.py
   - update gn/find_headers.py to write paths from the top
   - update gn/gn_to_bp.py SkUserConfig.h layout
     so that #include "include/config/SkUserConfig.h" always
     gets the header we want.

No-Presubmit: true
Change-Id: I73a4b181654e0e38d229bc456c0d0854bae3363e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209706
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
diff --git a/src/codec/SkHeifCodec.h b/src/codec/SkHeifCodec.h
index d844f57..4b2f182 100644
--- a/src/codec/SkHeifCodec.h
+++ b/src/codec/SkHeifCodec.h
@@ -8,16 +8,16 @@
 #ifndef SkHeifCodec_DEFINED
 #define SkHeifCodec_DEFINED
 
-#include "SkCodec.h"
-#include "SkEncodedOrigin.h"
-#include "SkImageInfo.h"
-#include "SkSwizzler.h"
-#include "SkStream.h"
+#include "include/codec/SkCodec.h"
+#include "include/codec/SkEncodedOrigin.h"
+#include "include/core/SkImageInfo.h"
+#include "include/core/SkStream.h"
+#include "src/codec/SkSwizzler.h"
 
 #if __has_include("HeifDecoderAPI.h")
     #include "HeifDecoderAPI.h"
 #else
-    #include "SkStubHeifDecoderAPI.h"
+    #include "src/codec/SkStubHeifDecoderAPI.h"
 #endif
 
 class SkHeifCodec : public SkCodec {