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/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 150a880..f5520d2 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -6,23 +6,23 @@
  * found in the LICENSE file.
  */
 
-#include "GrContextFactory.h"
-#include "GrContextPriv.h"
-#include "gl/GLTestContext.h"
+#include "src/gpu/GrContextPriv.h"
+#include "tools/gpu/GrContextFactory.h"
+#include "tools/gpu/gl/GLTestContext.h"
 
 #if SK_ANGLE
-    #include "gl/angle/GLTestContext_angle.h"
+    #include "tools/gpu/gl/angle/GLTestContext_angle.h"
 #endif
-#include "gl/command_buffer/GLTestContext_command_buffer.h"
+#include "tools/gpu/gl/command_buffer/GLTestContext_command_buffer.h"
 #ifdef SK_VULKAN
-#include "vk/VkTestContext.h"
+#include "tools/gpu/vk/VkTestContext.h"
 #endif
 #ifdef SK_METAL
-#include "mtl/MtlTestContext.h"
+#include "tools/gpu/mtl/MtlTestContext.h"
 #endif
-#include "gl/GrGLGpu.h"
-#include "mock/MockTestContext.h"
-#include "GrCaps.h"
+#include "src/gpu/GrCaps.h"
+#include "src/gpu/gl/GrGLGpu.h"
+#include "tools/gpu/mock/MockTestContext.h"
 
 #if defined(SK_BUILD_FOR_WIN) && defined(SK_ENABLE_DISCRETE_GPU)
 extern "C" {