Reduce webview provider switching overhead on fleet by reducing cts shard count.

Bug: 1021665
Change-Id: I4bb27606a3e52ec08341332f1844c6b0073994b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1970082
Commit-Queue: Andrew Luo <aluo@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726242}

testing/buildbot/chromium.android.fyi.json

@@ -211,7 +211,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -9118,7 +9118,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"

testing/buildbot/chromium.android.json

@@ -152,7 +152,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -207,7 +207,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -453,7 +453,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -507,7 +507,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -797,7 +797,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -851,7 +851,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -1237,7 +1237,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -1291,7 +1291,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -1677,7 +1677,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -1731,7 +1731,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"
@@ -36889,7 +36889,7 @@
               "name": "shard #${SHARD_INDEX} logcats"
             }
           ],
-          "shards": 3
+          "shards": 2
         },
         "test": "webview_cts_tests",
         "test_target": "//android_webview/test:webview_cts_tests"

testing/buildbot/test_suites.pyl

@@ -5091,7 +5091,7 @@
     'webview_cts_tests_gtest': {
       'webview_cts_tests': {
         'swarming': {
-          'shards': 3,
+          'shards': 2,
           'cipd_packages': [
             {
               "cipd_package": 'chromium/android_webview/tools/cts_archive',
@@ -5109,7 +5109,7 @@
           '--disable-field-trial-config',
         ],
         'swarming': {
-          'shards': 3,
+          'shards': 2,
           'cipd_packages': [
             {
               "cipd_package": 'chromium/android_webview/tools/cts_archive',