Specifying master names with "master." prefix is deprecated

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 65ac7b03b0c761701752bbad4f682a8862877700..1412b2b95f09222efe8a8e27c93618ecc4ac8377 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -41,11 +41,11 @@ GOLD_TRYBOT_URL = 'https://gold.skia.org/search?issue='
 # Path to CQ bots feature is described in https://bug.skia.org/4364
 PATH_PREFIX_TO_EXTRA_TRYBOTS = {
     # pylint: disable=line-too-long
-    'cmake/': 'client.skia.compile:Build-Mac-Clang-x86_64-Release-CMake-Trybot,Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot',
+    'cmake/': 'master.client.skia.compile:Build-Mac-Clang-x86_64-Release-CMake-Trybot,Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot',
     # pylint: disable=line-too-long
-    'src/opts/': 'client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot',
+    'src/opts/': 'master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot',
 
-    'include/private/SkAtomics.h': ('client.skia:'
+    'include/private/SkAtomics.h': ('master.client.skia:'
       'Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-TSAN-Trybot,'
       'Test-Ubuntu-GCC-Golo-GPU-GT610-x86_64-Release-TSAN-Trybot'
     ),