GN: Build libvpx

* Changes the include order of YASM
Default includes need to be put to the end for YASM.

In particular there are several versions of x86inc.asm in the tree and
libvpx requires its own version. This change in order allows libvpx to
include its own version.

* Roll libvpx to include BUILD.gn.

libvpx now builds on x86 posix.

R=brettw@chromium.org, scherkus@chromium.org, tomfinegan@chromium.org

Review URL: https://codereview.chromium.org/535613002

Cr-Commit-Position: refs/heads/master@{#294932}

DEPS

@@ -33,7 +33,7 @@ vars = {
   'pdfium_git': 'https://pdfium.googlesource.com',
   'skia_git': 'https://skia.googlesource.com',
   'boringssl_git': 'https://boringssl.googlesource.com',
-  'libvpx_revision': 'd95585fb0ec024f6abd96f7b02e0df58019d46af', # r291859
+  'libvpx_revision': '4947d55857acf2bf968016a7a00fe2b10fd52131',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
   'skia_revision': 'f0ddf33f1954489d45e4f2d9c8712eac60539c65',
   # Three lines of non-changing comments so that

media/cast/BUILD.gn

@@ -126,18 +126,17 @@ source_set("sender") {
     "sender/video_encoder_impl.cc",
     "sender/video_sender.h",
     "sender/video_sender.cc",
-#    "sender/vp8_encoder.cc",
-#    "sender/vp8_encoder.h",
+    "sender/vp8_encoder.cc",
+    "sender/vp8_encoder.h",
   ]
 
   deps = [
     ":common",
     ":net",
     "//media",
     "//media:shared_memory_support",
+    "//third_party/libvpx",
     "//third_party/opus",
-# TODO(hclam): libvpx support.
-#    "//third_party/libvpx",
   ]
 }
 
@@ -146,14 +145,12 @@ source_set("receiver") {
     "cast_receiver.h",
     "receiver/audio_decoder.cc",
     "receiver/audio_decoder.h",
-# TODO(hclam): Libvpx support.
-#    "receiver/cast_receiver_impl.cc",
-#    "receiver/cast_receiver_impl.h",
+    "receiver/cast_receiver_impl.cc",
+    "receiver/cast_receiver_impl.h",
     "receiver/frame_receiver.cc",
     "receiver/frame_receiver.h",
-# TODO(hclam): Need libvpx support.
-#    "receiver/video_decoder.cc",
-#    "receiver/video_decoder.h",
+    "receiver/video_decoder.cc",
+    "receiver/video_decoder.h",
   ]
 
   deps = [
@@ -162,8 +159,7 @@ source_set("receiver") {
     "//media",
     "//media:shared_memory_support",
     "//third_party/opus",
-# TODO(hclam): libvpx support.
-#    "//third_party/libvpx",
+    "//third_party/libvpx",
     "//ui/gfx",
   ]
 }
@@ -188,9 +184,8 @@ source_set("test_support") {
     "test/utility/barcode.h",
     "test/utility/default_config.cc",
     "test/utility/default_config.h",
-# TODO(hclam): libvpx support.
-#    "test/utility/in_process_receiver.cc",
-#    "test/utility/in_process_receiver.h",
+    "test/utility/in_process_receiver.cc",
+    "test/utility/in_process_receiver.h",
     "test/utility/input_builder.cc",
     "test/utility/input_builder.h",
     "test/utility/net_utility.cc",
@@ -253,16 +248,14 @@ test("cast_unittests") {
     "net/udp_transport_unittest.cc",
     "receiver/audio_decoder_unittest.cc",
     "receiver/frame_receiver_unittest.cc",
-# TODO(hclam): libvpx support.
-#    "receiver/video_decoder_unittest.cc",
+    "receiver/video_decoder_unittest.cc",
     "sender/audio_encoder_unittest.cc",
     "sender/audio_sender_unittest.cc",
     "sender/congestion_control_unittest.cc",
     "sender/external_video_encoder_unittest.cc",
-# TODO(hclam): libvpx support.
-#    "sender/video_encoder_impl_unittest.cc",
-#    "sender/video_sender_unittest.cc",
-#    "test/end2end_unittest.cc",
+    "sender/video_encoder_impl_unittest.cc",
+    "sender/video_sender_unittest.cc",
+    "test/end2end_unittest.cc",
     "test/fake_receiver_time_offset_estimator.cc",
     "test/fake_receiver_time_offset_estimator.h",
     "test/fake_video_encode_accelerator.cc",

media/media_options.gni

@@ -16,7 +16,7 @@ linux_link_pulseaudio = false
 
 # TODO(ajwong): Enable libvpx once that's converted.
 media_use_ffmpeg = true
-media_use_libvpx = false
+media_use_libvpx = true
 if (is_android || is_ios) {
   # Android and iOS don't use ffmpeg or libvpx.
   media_use_ffmpeg = false

third_party/yasm/yasm_assemble.gni

@@ -81,18 +81,6 @@ if (is_mac || is_ios) {
   }
 }
 
-# Default yasm include dirs. Make it match the native build (source root and
-# root generated code directory).
-_yasm_flags += [
-  "-I.",
-  # Using "//." will produce a relative path "../.." which looks better than
-  # "../../" which will result from using "//" as the base (although both
-  # work). This is because rebase_path will terminate the result in a slash if
-  # the input ends in a slash.
-  "-I" + rebase_path("//.", root_build_dir),
-  "-I" + rebase_path(root_gen_dir, root_build_dir),
-]
-
 if (is_win) {
   asm_obj_extension = "obj"
 } else {
@@ -142,13 +130,26 @@ template("yasm_assemble") {
       args += invoker.yasm_flags
     }
 
-    # Extra include directories.
+    # User defined include dirs go first.
     if (defined(invoker.include_dirs)) {
       foreach(include, invoker.include_dirs) {
         args += [ "-I" + rebase_path(include, root_build_dir) ]
       }
     }
 
+    # Default yasm include dirs. Make it match the native build (source root and
+    # root generated code directory).
+    # This goes to the end of include list.
+    args += [
+      # Using "//." will produce a relative path "../.." which looks better than
+      # "../../" which will result from using "//" as the base (although both
+      # work). This is because rebase_path will terminate the result in a
+      # slash if the input ends in a slash.
+      "-I" + rebase_path("//.", root_build_dir),
+      "-I" + rebase_path(root_gen_dir, root_build_dir),
+    ]
+
+
     # Extra defines.
     if (defined(invoker.defines)) {
       foreach(def, invoker.defines) {