Replace WIDEVINE_CDM_AVAILABLE with a gyp define 'enable_widevine_cdm'.

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1962 matching lines @@
       }, {
         'enable_pepper_cdms%': 0,
       }],
 
       ['OS=="android"', {
         'enable_browser_cdms%': 1,
       }, {
         'enable_browser_cdms%': 0,
       }],
 
+      # Widevine CDM is enabled by default for Chrome builds, and is a platform
+      # feature on Android.
+      ['branding=="Chrome" or OS="android"', {
+        'enable_widevine': 1,
+      }, {
+        'enable_widevine': 0,

[lcwu1, 2014/12/02 23:23:16]

Drive-by comment: Could you add '%' to the gyp variable so that it can be
overridden by different platforms/implementations.

[sandersd (OOO until July 31), 2014/12/12 01:34:46]

Done.

+      }],
+
+      # Widevine is distributed as a component for Mac and Win.

[ddorwin, 2014/12/02 23:31:56]

This is only for Chrome. I guess we should make this 'branding=="Chrome" and
(...)

+      ['OS=="mac" or OS=="win"', {
+        'widevine_cdm_is_component': 1,
+      }, {
+        'widevine_cdm_is_component': 0,
+      }],
+
       # Native Client glibc toolchain is enabled
       # by default except on arm, mips and mips64.
       ['target_arch=="arm" or target_arch=="mipsel" or target_arch=="mips64el"', {
         'disable_glibc%': 1,
       }, {
         'disable_glibc%': 0,
       }],
 
       # Set the relative path from this file to the GYP file of the JPEG
       # library used by Chromium.
@@ skipping 656 matching lines @@
       }],
       ['enable_viewport==1', {
         'defines': ['ENABLE_VIEWPORT'],
       }],
       ['enable_pepper_cdms==1', {
         'defines': ['ENABLE_PEPPER_CDMS'],
       }],
       ['enable_browser_cdms==1', {
         'defines': ['ENABLE_BROWSER_CDMS'],
       }],
+      ['enable_widevine==1', {

[DaleCurtis, 2014/12/02 22:58:38]

These are global defines which should always be reluctantly added.  Is there any
way to avoid this at global scope? Can it be limited to just media/ and
third_party/widevine easily?

[sandersd (OOO until July 31), 2014/12/02 23:04:44]

I don't know. There is no common include that I am aware of, but I suspect we
can add includes until it's possible.

This specific define is used in chromecast, content/renderer, chrome/browser,
chrome/common, chrome/renderer.

[DaleCurtis, 2014/12/02 23:12:17]

Ah, that's unfortunate. Do all of these users depend directly on media? You can
then use dependent configs to keep these in media/ only.  See how libvpx
disabling is done across content/renderer and media/ and media/blink

https://code.google.com/p/chromium/codesearch#search/&q=MEDIA_DISABLE_LIBVPX

[lcwu1, 2014/12/02 23:23:16]

Chromecast uses the define. We do depend on media/ directly. So as long as the
define is exposed to chromecast/, either way is fine.

[ddorwin, 2014/12/02 23:31:56]

Looking at the paths in this CL, there are some that do not appear to depend on
media.gyp. We could create a new target or .gyp file for those, though I'm not
sure how best to do that. How close are we to transitioning to GN? Does it make
sense do focus on doing this in GN?

[DaleCurtis, 2014/12/03 01:11:00]

Which targets don't depend on media? third_party/widevine seems like it might
the only one. Of which media depends on, so perhaps it should host all these
defines? media/ can then propagate them outward to its dependents.

[ddorwin, 2014/12/03 01:29:45]

As an example, from a brief look, it was not clear that files from
chrome/common. and chrome/renderer. in this CL depend on media.gyp.

[DaleCurtis, 2014/12/04 02:45:08]

I see, I misread the paths, yeah I don't think a direct dependent setting would
reach those. 

+        'defines': ['ENABLE_WIDEVINE'],
+      }],
+      ['widevine_cdm_is_component==1', {
+        'defines': ['WIDEVINE_CDM_IS_COMPONENT'],
+      }],
       ['configuration_policy==1', {
         'defines': ['ENABLE_CONFIGURATION_POLICY'],
       }],
       ['notifications==1', {
         'defines': ['ENABLE_NOTIFICATIONS'],
       }],
       ['enable_hidpi==1', {
         'defines': ['ENABLE_HIDPI=1'],
       }],
       ['native_discardable_memory==1', {
@@ skipping 3190 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }