[Sync] Move //sync to //components/sync.

There are a bunch of subfolder reorganizations going along with this:

- engine/ -> engine_impl/
- sessions/ -> sessions_impl/
- util/ -> base/
- internal_api/public/base/ -> base/
- internal_api/public/sessions/ -> sessions/
- internal_api/public/engine/ -> engine/
- internal_api/public/events/ -> engine/events/
- internal_api/public/util/ -> base/
- internal_api/public/ -> core/
- internal_api/ -> core_impl/

This change was generated using the following script:
http://pastebin.com/vVAkRCkh

Because this patch is so large, some review was done in split CLs:

Manual changes: http://crrev.com/2155763002
Sync internal changes: http://crrev.com/2156693002
Sync external changes: http://crrev.com/2148293004

This is a minimal change to support file movement; it doesn't do
anything like merging sync_unit_tests into component_unit_tests,
which will be done in a followup.

The gyp files are not sorted because they're all going to be removed
very soon anyways.

BUG=626114
[email protected], [email protected]
TBR=jam

Review URL: https://codereview.chromium.org/2130453004 .

Cr-Commit-Position: refs/heads/master@{#408497}
diff --git a/BUILD.gn b/BUILD.gn
index 8bf24cc..f5080c97 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -126,13 +126,13 @@
       "//base:base_unittests",
       "//chrome/test:browser_tests",
       "//chrome/test:sync_integration_tests",
+      "//components/sync:sync_unit_tests",
       "//ipc:ipc_tests",
       "//media:media_unittests",
       "//media/midi:midi_unittests",
       "//net:net_unittests",
       "//printing:printing_unittests",
       "//sql:sql_unittests",
-      "//sync:sync_unit_tests",
       "//ui/base:ui_base_unittests",
       "//ui/gfx:gfx_unittests",
       "//ui/touch_selection:ui_touch_selection_unittests",
@@ -181,10 +181,10 @@
     "//base:base_unittests",
     "//chrome/installer",
     "//components:components_unittests",
+    "//components/sync:sync_unit_tests",
     "//net:net_unittests",
     "//skia:skia_unittests",
     "//sql:sql_unittests",
-    "//sync:sync_unit_tests",
     "//tools/ipc_fuzzer:ipc_fuzzer_all",
     "//ui/base:ui_base_unittests",
     "//ui/gfx:gfx_unittests",
@@ -205,6 +205,8 @@
       "//chrome/test:interactive_ui_tests",
       "//chrome/test:sync_integration_tests",
       "//chrome/test/chromedriver:chromedriver_unittests",
+      "//components/sync/tools:sync_client",
+      "//components/sync/tools:sync_listen_notifications",
       "//extensions:extensions_browsertests",
       "//extensions:extensions_unittests",
       "//gpu/gles2_conform_support:gles2_conform_test",
@@ -243,8 +245,6 @@
       "//ppapi/examples/video_effects",
       "//ppapi/examples/video_encode",
       "//printing:printing_unittests",
-      "//sync/tools:sync_client",
-      "//sync/tools:sync_listen_notifications",
       "//third_party/cacheinvalidation:cacheinvalidation_unittests",
       "//third_party/codesighs",
       "//third_party/pdfium/samples:pdfium_test",
@@ -504,6 +504,7 @@
       "//cc:cc_perftests",
       "//cc/blink:cc_blink_unittests",
       "//components:components_perftests",
+      "//components/sync:run_sync_testserver",
       "//device:device_unittests",
       "//gin:gin_shell",
       "//gin:gin_unittests",
@@ -513,7 +514,6 @@
       "//ipc:ipc_perftests",
       "//media:media_perftests",
       "//net:dump_cache",
-      "//sync:run_sync_testserver",
       "//third_party/angle/src/tests:angle_end2end_tests",
       "//third_party/angle/src/tests:angle_unittests",
       "//third_party/codesighs:maptsvdifftool",