Fixing dependency problem for the mojo Range class

The mojo Range class needs range_struct_traits.h and the build
system wasn't setup to allow that. Simplest for everyone is to integrate
the struct_traits target into the mojom target and let the mojo system
figure out dependencies. This made everything simpler.

Without this fix you got errors like the one below:

ERROR at //out/Default/gen/content/common/input/input_handler.mojom-test-utils.cc:49:11: Can't include this header from here.
          ^--------------------------------------
The target:
  //content/common:mojo_bindings
is including a file from the target:
  //ui/gfx/range/mojo:struct_traits

It's usually best to depend directly on the destination target.
In some cases, the destination target is considered a subcomponent
of an intermediate target. In this case, the intermediate target
should depend publicly on the destination to forward the ability
to include headers.

Dependency chain (there may also be others):
  //content/common:mojo_bindings -->
  //services/ws/public/mojom/ime:ime --[private]-->
  //ui/gfx/range/mojo:struct_traits

Bug: 938893
Change-Id: If01554d38ca3d5f4280d32c658d1f7044f14c29e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1536056Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#644390}

ash/public/interfaces/app_list.typemap

@@ -8,9 +8,6 @@ traits_headers = [ "//ash/public/cpp/app_list/app_list_struct_traits.h" ]
 sources = [
   "//ash/public/cpp/app_list/app_list_struct_traits.cc",
 ]
-deps = [
-  "//ui/gfx/range/mojo:struct_traits",
-]
 type_mappings = [
   "ash.mojom.AppListState=ash::AppListState",
   "ash.mojom.AppListModelStatus=ash::AppListModelStatus",

services/ws/public/mojom/BUILD.gn

@@ -65,6 +65,5 @@ source_set("tests") {
     "//services/ws/public/mojom/ime",
     "//testing/gtest",
     "//ui/gfx:test_support",
-    "//ui/gfx/range/mojo:struct_traits",
   ]
 }

ui/accessibility/mojom/ax_assistant_structure.typemap

@@ -16,7 +16,6 @@ public_deps = [
   "//ui/gfx/geometry/mojo",
   "//ui/gfx/geometry/mojo:struct_traits",
   "//ui/gfx/range/mojo",
-  "//ui/gfx/range/mojo:struct_traits",
 ]
 type_mappings = [
   "ax.mojom.AssistantTree=std::unique_ptr<ui::AssistantTree>[move_only,nullable_is_same_type]",

ui/base/BUILD.gn

@@ -967,7 +967,6 @@ test("ui_base_unittests") {
     deps += [
       "//ui/base/ime",
       "//ui/base/ime/mojo:test_interfaces",
-      "//ui/gfx/range/mojo:struct_traits",
     ]
   }
 

ui/base/ime/mojo/ime_types.typemap

@@ -19,7 +19,6 @@ public_deps = [
 ]
 deps = [
   "//ui/gfx/range",
-  "//ui/gfx/range/mojo:struct_traits",
 ]
 
 type_mappings = [

ui/gfx/range/mojo/BUILD.gn

@@ -37,13 +37,3 @@ source_set("unit_test") {
     "//ui/gfx/range",
   ]
 }
-
-source_set("struct_traits") {
-  sources = [
-    "range_struct_traits.h",
-  ]
-  public_deps = [
-    ":mojo_shared_cpp_sources",
-    "//ui/gfx/range",
-  ]
-}

ui/gfx/range/mojo/OWNERS

+per-file *.mojom=set noparent
+per-file *.mojom=file://ipc/SECURITY_OWNERS
+
 per-file *_struct_traits*.*=set noparent
 per-file *_struct_traits*.*=file://ipc/SECURITY_OWNERS
 
-per-file *.mojom=set noparent
-per-file *.mojom=file://ipc/SECURITY_OWNERS
+per-file *.typemap=set noparent
+per-file *.typemap=file://ipc/SECURITY_OWNERS

ui/gfx/range/mojo/range.typemap

@@ -8,10 +8,13 @@ public_headers = [
   "//ui/gfx/range/range_f.h",
 ]
 traits_headers = [ "//ui/gfx/range/mojo/range_struct_traits.h" ]
-deps = [
-  "//ui/gfx/range/mojo:struct_traits",
-]
 type_mappings = [
   "gfx.mojom.Range=gfx::Range",
   "gfx.mojom.RangeF=gfx::RangeF",
 ]
+sources = [
+  "range_struct_traits.h",
+]
+deps = [
+  "//ui/gfx/range",
+]