Apply fixes for EfficientStrings.

Refactoring to avoid StringBuffer synchronization overhead.

Bug: 170978902
Test: none
Exempt-From-Owner-Approval: trivial refactoring
Change-Id: Ibf843ed780c1202d5d96a11eaca889e592f19263

1 files changed, 3 insertions, 3 deletions

diff --git a/core/java/android/os/Debug.java b/core/java/android/os/Debug.java
index a2e53e29193c..4fed93204f59 100644
--- a/core/java/android/os/Debug.java
+++ b/core/java/android/os/Debug.java
@@ -2468,7 +2468,7 @@ public final class Debug
     @UnsupportedAppUsage
     public static String getCallers(final int depth) {
         final StackTraceElement[] callStack = Thread.currentThread().getStackTrace();
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < depth; i++) {
             sb.append(getCaller(callStack, i)).append(" ");
         }
@@ -2483,7 +2483,7 @@ public final class Debug
      */
     public static String getCallers(final int start, int depth) {
         final StackTraceElement[] callStack = Thread.currentThread().getStackTrace();
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         depth += start;
         for (int i = start; i < depth; i++) {
             sb.append(getCaller(callStack, i)).append(" ");
@@ -2501,7 +2501,7 @@ public final class Debug
      */
     public static String getCallers(final int depth, String linePrefix) {
         final StackTraceElement[] callStack = Thread.currentThread().getStackTrace();
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < depth; i++) {
             sb.append(linePrefix).append(getCaller(callStack, i)).append("\n");
         }