GN: Fix test_support_unittests and MIPS compile issue.

Move the webrtc/test/test_support/metrics sources into
test_support[_unittests] targets.
This is essentially reverting https://webrtc-codereview.appspot.com/5789004
and moving these sources back to the right target.

Add missing foreman_cif.yuv resource needed for these tests.

For MIPS, a compile error was surfacing for logcat_trace_context.h when
flipping bot to GN, which was fixed.

BUG=webrtc:5949
NOTRY=True

Review-Url: https://codereview.webrtc.org/2267113002
Cr-Commit-Position: refs/heads/master@{#13860}

webrtc/modules/video_coding/codecs/tools/video_codecs_tools.gypi

@@ -19,7 +19,7 @@
             '<(DEPTH)/third_party/gflags/gflags.gyp:gflags',
             '<(webrtc_root)/common.gyp:webrtc_common',
             '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers_default',
-            '<(webrtc_root)/test/metrics.gyp:metrics',
+            '<(webrtc_root)/test/test.gyp:test_support',
             '<(webrtc_vp8_dir)/vp8.gyp:webrtc_vp8',
           ],
           'sources': [

webrtc/modules/video_coding/codecs/vp8/vp8.gyp

@@ -58,7 +58,6 @@
           'dependencies': [
             'webrtc_vp8',
             '<(webrtc_root)/common_video/common_video.gyp:common_video',
-            '<(webrtc_root)/test/metrics.gyp:metrics',
             '<(DEPTH)/testing/gtest.gyp:gtest',
             '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers',
             '<(webrtc_root)/test/test.gyp:test_support_main',