Fix ODR violation between media/gpu:common and ARC.

components/arc/video_accelerator:common included media/gpu:common as
a dep.  However, media/gpu:common is a source set.  It ends up
including all the code in media/gpu:common in the resulting ARC
shared object in addition to media/gpu one.  This would be okay, if
it were the one-definition guideline.

This CL replaces the dep with one on the component media/gpu:gpu.

      media/gpu:common symbols defined now.

Bug: 1109309
Test: 'gn check' is still happy, and only libmedia_gpu.so has the
Change-Id: I52d6d69956eb55a24df1cc97c11907e9b400d7c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2318686Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792588}

components/arc/video_accelerator/BUILD.gn

@@ -36,7 +36,7 @@ source_set("common") {
 
   deps = [
     "//media",
-    "//media/gpu:common",
+    "//media/gpu:gpu",
     "//mojo/public/cpp/system:system",
     "//ui/gfx:memory_buffer",
   ]

media/gpu/BUILD.gn

@@ -31,7 +31,7 @@ component("gpu") {
     "//chromecast/*",
     "//components/arc/mojom:media",
     "//components/arc/mojom:media_mojolpm",
-    "//components/arc/video_accelerator",
+    "//components/arc/video_accelerator:common",
     "//components/mirroring/service:mirroring_service",
     "//components/chromeos_camera/*",
     "//components/viz/service/main",
@@ -270,6 +270,11 @@ source_set("common") {
     "vp9_reference_frame_vector.h",
   ]
 
+  visibility = [
+    ":gpu",
+    "//media/gpu/*",
+  ]
+
   # TODO(crbug.com/1006266): consider using |use_chromeos_video_acceleration|.
   if (use_v4l2_codec || use_vaapi) {
     sources += [
@@ -357,7 +362,6 @@ if (is_android) {
 
     deps = [
       ":android_video_decode_accelerator_unittests",
-      ":common",
       ":gpu",
       "//base",
       "//base/test:test_support",
@@ -414,7 +418,6 @@ source_set("android_video_decode_accelerator_unittests") {
       "android/video_frame_factory_impl_unittest.cc",
     ]
     deps = [
-      ":common",
       ":gpu",
       "//base/test:test_support",
       "//gpu:test_support",