Add tbansal@ to histogram owners

The previous ownership in tools/metrics/histograms/OWNERS
is no longer relevant.

Change-Id: I3fe050c396011ae88c8766d8e259b8a32cf9c20b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2442094
Commit-Queue: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812946}

tools/metrics/histograms/histograms_xml/data_reduction_proxy/OWNERS

+# If these reviewers are unavailable, please send CLs to
+# <chromium-metrics-reviews@google.com>. See tools/metrics/histograms/OWNERS
+# for details.
+tbansal@chromium.org
+
+# COMPONENT: Internals>Network>DataProxy

tools/metrics/histograms/histograms_xml/navigation/OWNERS

+# Prefer chromium-metrics-reviews@google.com instead.
+# Use the following owners only if:
+#  - The reviewer is available for review.
+#  - You work in the same area as them.
+#  - They are already a good reviewer for the non-metrics part of the CL.
+# See tools/metrics/histograms/OWNERS for details.
+tbansal@chromium.org

tools/metrics/histograms/histograms_xml/optimization/OWNERS

+# If these reviewers are unavailable, please send CLs to
+# <chromium-metrics-reviews@google.com>. See tools/metrics/histograms/OWNERS
+# for details.
+tbansal@chromium.org
+
+# COMPONENT: Internals>OptimizationGuide

tools/metrics/histograms/histograms_xml/others/OWNERS

+# Prefer chromium-metrics-reviews@google.com instead.
+# Use the following owners only if:
+#  - The reviewer is available for review.
+#  - You work in the same area as them.
+#  - They are already a good reviewer for the non-metrics part of the CL.
+# See tools/metrics/histograms/OWNERS for details.
+tbansal@chromium.org

tools/metrics/histograms/histograms_xml/subresource/OWNERS

+# Prefer chromium-metrics-reviews@google.com instead.
+# Use the following owners only if:
+#  - The reviewer is available for review.
+#  - You work in the same area as them.
+#  - They are already a good reviewer for the non-metrics part of the CL.
+# See tools/metrics/histograms/OWNERS for details.
+tbansal@chromium.org

tools/metrics/histograms/histograms_xml/translate/OWNERS

+# If these reviewers are unavailable, please send CLs to
+# <chromium-metrics-reviews@google.com>. See tools/metrics/histograms/OWNERS
+# for details.
+tbansal@chromium.org
+
+# COMPONENT: UI>Browser>Language>Translate