Make Linker.isUsed() static, and clean up the fallout.

content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java

Index: content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java
diff --git a/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java b/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java
index 3ab54cbb99c854dbec1e69109170d9c991f437c4..f2f4dcc34084ff4c8e9a31569636df5fe5149093 100644
--- a/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java
+++ b/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestActivity.java
@@ -97,11 +97,14 @@ public class ChromiumLinkerTestActivity extends Activity {
             finish();
         }
 
-        // Set the requested Linker implementation from the command-line.
+        // Set the requested Linker implementation from the command-line, and
+        // register the test runner class by name.
         if (hasModernLinkerSwitch) {
-            Linker.setLinkerImplementationForTesting(Linker.LINKER_IMPLEMENTATION_MODERN);
+            Linker.setupForTesting(Linker.LINKER_IMPLEMENTATION_MODERN,
+                                   LinkerTests.class.getName());
         } else {
-            Linker.setLinkerImplementationForTesting(Linker.LINKER_IMPLEMENTATION_LEGACY);
+            Linker.setupForTesting(Linker.LINKER_IMPLEMENTATION_LEGACY,
+                                   LinkerTests.class.getName());
         }
 
         // Determine which kind of device to simulate from the command-line.
@@ -112,9 +115,6 @@ public class ChromiumLinkerTestActivity extends Activity {
         Linker linker = Linker.getInstance();
         linker.setMemoryDeviceConfigForTesting(memoryDeviceConfig);
 
-        // Register the test runner class by name.
-        linker.setTestRunnerClassNameForTesting(LinkerTests.class.getName());
-
         // Load the library in the browser process, this will also run the test
         // runner in this process.
         try {