Fix build with system yasm.

BUG=100078
Review URL: http://codereview.chromium.org/8243012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@105149 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -26,8 +26,8 @@ vars = {
   "nacl_toolchain_revision": "6757",
 
   "libjingle_revision": "85",
-  "libvpx_revision": "103347",
-  "ffmpeg_revision": "103983",
+  "libvpx_revision": "105133",
+  "ffmpeg_revision": "105133",
   "sfntly_revision": "98",
   "skia_revision": "2465",
   "v8_revision": "9586",
@@ -257,7 +257,7 @@ deps = {
     "/trunk/deps/third_party/yasm/patched-yasm@73761",
 
   "src/third_party/libjpeg_turbo":
-    "/trunk/deps/third_party/libjpeg_turbo@102926",
+    "/trunk/deps/third_party/libjpeg_turbo@105131",
 
   "src/third_party/flac":
     "/trunk/deps/third_party/flac@96404",

build/common.gypi

@@ -383,6 +383,9 @@
     # Whether to build for Wayland display server
     'use_wayland%': 0,
 
+    # Use system yasm instead of bundled one.
+    'use_system_yasm%': 0,
+
     # Default to enabled PIE; this is important for ASLR but we need to be
     # able to turn it off for remote debugging on Chromium OS
     'linux_disable_pie%': 0,

third_party/yasm/yasm_compile.gypi

@@ -27,9 +27,14 @@
 {
   'variables': {
     'yasm_flags': [],
-    'yasm_path': '<(PRODUCT_DIR)/yasm',
 
     'conditions': [
+      [ 'use_system_yasm==0', {
+        'yasm_path': '<(PRODUCT_DIR)/yasm',
+      }, {
+        'yasm_path': '<!(which yasm)',
+      }],
+
       # Define yasm_flags that pass into YASM.
       [ 'OS=="linux" and target_arch=="ia32"', {
         'yasm_flags': [
@@ -70,7 +75,7 @@
   'conditions': [
     # Only depend on YASM on x86 systems, do this so that compiling
     # .asm files for ARM will fail.
-    ['target_arch=="ia32" or target_arch=="x64"', {
+    ['use_system_yasm==0 and ( target_arch=="ia32" or target_arch=="x64" )', {
       'dependencies': [
         '<(DEPTH)/third_party/yasm/yasm.gyp:yasm#host',
       ],