DevTools: do not use platform/ to load injected scripts into inspector/v8.

third_party/WebKit/Source/core/inspector/v8/BUILD.gn

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+v8_inspector_output_dir = "$root_gen_dir/blink/core/inspector/v8"
+
+group("injected_script_sources") {
+  public_deps = [
+    ":debugger_script",
+    ":injected_script",
+  ]
+}
+
+action("injected_script") {
+  script = "build/xxd.py"
+  inputs = [
+    "InjectedScriptSource.js",
+  ]
+  outputs = [
+    "$v8_inspector_output_dir/InjectedScriptSource.h",
+  ]
+  args = [
+    "InjectedScriptSource_js",
+    rebase_path("InjectedScriptSource.js", root_build_dir),
+    rebase_path("$v8_inspector_output_dir/InjectedScriptSource.h",
+                root_build_dir),
+  ]
+}
+
+action("debugger_script") {
+  script = "build/xxd.py"
+  inputs = [
+    "DebuggerScript.js",
+  ]
+  outputs = [
+    "$v8_inspector_output_dir/DebuggerScript.h",
+  ]
+  args = [
+    "DebuggerScript_js",
+    rebase_path("DebuggerScript.js", root_build_dir),
+    rebase_path("$v8_inspector_output_dir/DebuggerScript.h", root_build_dir),
+  ]
+}