Add chromecast_build gyp variable and add rules when the variable is set to 1.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 1308a1d5a20e6efd81f13d27dd816df342fbff3b..f8eade5972d21798cf52bce4f277fe3e7eb371a6 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -158,6 +158,10 @@
         # build system.
         'android_webview_build%': 0,
 
+        # This is set when building Chromecast using the build environment
+        # and scripts inside Chromecast directory.
+        'chromecast_build%': 0,
+
         # Set ARM architecture version.
         'arm_version%': 7,
 
@@ -268,6 +272,7 @@
       'enable_viewport%': '<(enable_viewport)',
       'enable_hidpi%': '<(enable_hidpi)',
       'android_webview_build%': '<(android_webview_build)',
+      'chromecast_build%': '<(chromecast_build)',
       'use_goma%': '<(use_goma)',
       'gomadir%': '<(gomadir)',
       'enable_app_list%': '<(enable_app_list)',
@@ -1037,6 +1042,7 @@
     'use_libjpeg_turbo%': '<(use_libjpeg_turbo)',
     'use_system_libjpeg%': '<(use_system_libjpeg)',
     'android_webview_build%': '<(android_webview_build)',
+    'chromecast_build%': '<(chromecast_build)',
     'icu_use_data_file_flag%': '<(icu_use_data_file_flag)',
     'gyp_managed_install%': 0,
     'create_standalone_apk%': 1,
@@ -2493,6 +2499,22 @@
           }],
         ],  # win_z7!=0
       }],  # OS==win
+      ['chromecast_build==1', {
+        'defines': [
+          'CHROMECAST_BUILD',

[darin (slow to review), 2014/04/14 04:50:35]

I think it would be nice to see if we could solve for Chromecast without
introducing an #ifdef. I realize that we have #ifdefs for other ports, but
adding an #ifdef for every port just doesn't scale. Each has its own recipe of
things to enable / disable. We have likewise resisted an OPERA_BUILD #ifdef.

Looking over the various patches I have seen it seems like it should be possible
to extract code into separate files, eliminating #ifdefs in favor of selecting
the right .cc files at build time.

+          'LOG_DISABLED=0',
+          'ENABLE_MPEG2TS_STREAM_PARSER',

[damienv1, 2014/04/03 21:45:33]

There is now a gyp parameter the mpeg2 TS parser: enable_mpeg2ts_stream_parser.
See https://codereview.chromium.org/216423008/

+        ],
+        'conditions': [
+          ['target_arch=="arm"', {
+            'defines': [
+              # Work around an error when compiling v8/src/platform-linux.cc
+              # with gcc-4.5.
+              '__SOFTFP',
+            ],
+          }],
+        ],
+      }],
       ['enable_task_manager==1', {
         'defines': [
           'ENABLE_TASK_MANAGER=1',
@@ -3472,6 +3494,32 @@
                       }],
                     ],
                   }],
+                  ['chromecast_build==1', {
+                    'cflags': [
+                      # We set arm_arch to "" so that -march compiler option
+                      # is not set.  Otherwise a gcc bug that would complain
+                      # about it conflicting with '-mcpu=cortex-a9'. The flag
+                      # '-march=armv7-a' is actually redundant anyway because
+                      # it is enabled by default when we built the toolchain.
+                      # And using '-mcpu=cortex-a9' should be sufficient.
+                      '-mcpu=cortex-a9',
+                      '-funwind-tables',
+                      # Breakpad requires symbols with debugging information
+                      '-g',
+                    ],
+                    'ldflags': [
+                      # We want to statically link libstdc++/libgcc_s.
+                      '-static-libstdc++',
+                      '-static-libgcc',
+                    ],
+                    'cflags!': [
+                      # Some components in Chormium (e.g. v8) define their own
+                      # cflags that are not desirable. Remove them explicitly
+                      # here.
+                      '-march=armv7-a',
+                      '-mtune=cortex-a8',
+                    ],
+                  }],
                 ],
               }],
             ],