Remove dependency of common on variations browser code

components/variations.gypi

Index: components/variations.gypi
diff --git a/components/variations.gypi b/components/variations.gypi
index c3589aea4ba12150939c4324d7cb59f6bbdf4d33..5d20b5bf2acc21d5c6cab2d645923acbdb762822 100644
--- a/components/variations.gypi
+++ b/components/variations.gypi
@@ -5,8 +5,8 @@
 {
   'targets': [
     {
-      # GN version: //components/variations
-      'target_name': 'variations',
+      # GN version: //components/variations_common
+      'target_name': 'variations_common',

[Alexei Svitkine (slow), 2014/08/21 21:07:10]

I'd keep this as 'variations'.

[scottmg, 2014/08/21 21:21:48]

Done.

(Was based on many other components (see chrome_common) having a similar naming
scheme.)

       'type': 'static_library',
       'include_dirs': [
         '..',
@@ -14,7 +14,6 @@
       'dependencies': [
         '../base/base.gyp:base',

[Alexei Svitkine (slow), 2014/08/21 21:07:10]

Would you mind adding the following comment at the top of the file? (To avoid
this library accidentally getting more dependencies as it happened in the case
with the header provider.)

# List of dependencies is intentionally very minimal. Please avoid adding extra
# dependencies without first checking with OWNERS.

[scottmg, 2014/08/21 21:21:48]

Done.

         '../third_party/mt19937ar/mt19937ar.gyp:mt19937ar',
-        'components.gyp:google_core_browser',
       ],
       'sources': [
         'variations/active_field_trials.cc',
@@ -41,8 +40,6 @@
         'variations/study_filtering.h',
         'variations/variations_associated_data.cc',
         'variations/variations_associated_data.h',
-        'variations/variations_http_header_provider.cc',
-        'variations/variations_http_header_provider.h',
         'variations/variations_seed_processor.cc',
         'variations/variations_seed_processor.h',
         'variations/variations_seed_simulator.cc',
@@ -61,6 +58,24 @@
         }],
       ],
     },
+    {
+      # GN version: //components/variations
+      'target_name': 'variations',

[Alexei Svitkine (slow), 2014/08/21 21:07:10]

I'd name this variations_http_provider, since that's the only thing it has at
this point. (I can revisit the name if/when more files are added to this
target).

Then, only chrome/browser that needs it can depend on this (in addition to the
variations target, since that's needed because chrome/browser still uses its
protos.)

[scottmg, 2014/08/21 21:21:48]

Done.

+      'type': 'static_library',
+      'include_dirs': [
+        '..',
+      ],
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../third_party/mt19937ar/mt19937ar.gyp:mt19937ar',

[Alexei Svitkine (slow), 2014/08/21 21:07:10]

I don't think this dependency is needed.

[scottmg, 2014/08/21 21:21:48]

Done.

+        'components.gyp:google_core_browser',
+        'variations_common',
+      ],
+      'sources': [
+        'variations/variations_http_header_provider.cc',
+        'variations/variations_http_header_provider.h',
+      ],
+    },
   ],
   'conditions': [
     ['OS=="android"', {