[Device Service] Move Gamepad Blink headers to be part of the Gamepad client library

content/test/layouttest_support.cc

Index: content/test/layouttest_support.cc
diff --git a/content/test/layouttest_support.cc b/content/test/layouttest_support.cc
index daa6d5cd24eb1bedd9b9af925b5bd77e851b900f..8d6a1098f68189d73af71ab1a747ce7fe3ddda96 100644
--- a/content/test/layouttest_support.cc
+++ b/content/test/layouttest_support.cc
@@ -45,7 +45,6 @@
 #include "gpu/ipc/service/image_transport_surface.h"
 #include "services/ui/public/cpp/gpu/context_provider_command_buffer.h"
 #include "third_party/WebKit/public/platform/WebFloatRect.h"
-#include "third_party/WebKit/public/platform/WebGamepads.h"
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/platform/scheduler/test/renderer_scheduler_test_support.h"
@@ -69,8 +68,6 @@
 
 using device::MotionData;
 using device::OrientationData;
-using blink::WebGamepad;
-using blink::WebGamepads;
 using blink::WebRect;
 using blink::WebSize;