Separate the generated files from core and modules to their own sub-dirs.

Source/modules/modules.gypi

Index: Source/modules/modules.gypi
diff --git a/Source/modules/modules.gypi b/Source/modules/modules.gypi
index a6bc0398647228ec1bbd35e011c1b634cc4fd247..51ab84769a1cf64c6086503a6626dd37464433e9 100644
--- a/Source/modules/modules.gypi
+++ b/Source/modules/modules.gypi
@@ -264,15 +264,15 @@
     ],
     'generated_modules_files': [
       # .cpp files from make_modules_generated actions.
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventModules.cpp',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventModulesHeaders.h',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventModulesInterfaces.h',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventModulesNames.cpp',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventModulesNames.h',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventTargetModulesHeaders.h',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventTargetModulesInterfaces.h',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventTargetModulesNames.cpp',
-      '<(SHARED_INTERMEDIATE_DIR)/blink/EventTargetModulesNames.h',
+      '<(modules_output_dir)/EventModules.cpp',
+      '<(modules_output_dir)/EventModulesHeaders.h',
+      '<(modules_output_dir)/EventModulesInterfaces.h',
+      '<(modules_output_dir)/EventModulesNames.cpp',
+      '<(modules_output_dir)/EventModulesNames.h',
+      '<(modules_output_dir)/EventTargetModulesHeaders.h',
+      '<(modules_output_dir)/EventTargetModulesInterfaces.h',
+      '<(modules_output_dir)/EventTargetModulesNames.cpp',
+      '<(modules_output_dir)/EventTargetModulesNames.h',
     ],
     'modules_files': [
       '<@(extra_blink_module_files)',