[Android] Initialize CommandLine before any usage in Render.

On low-end devices, if Chrome was upgraded from a previous version,
Chrome decides to use normal mode to keep user experience consistent.
This is done by force '--low-end-device-mode=0' on both browser and render
processes.

However, when crazy linker is used, Linker.isUsed() triggers
SysUtils.detectLowEndDevice() call which checks CommandLine first.
Existing code invokes Linker.isUsed() before initilizing CommandLine,
which causes the render process ignores '--low-end-device-mode=0'.

This results the browser in normal mode, but render is in low-end device mode.

BUG=424228

Review URL: https://codereview.chromium.org/665273003

Cr-Commit-Position: refs/heads/master@{#301581}

base/android/java/src/org/chromium/base/SysUtils.java

@@ -103,13 +103,12 @@ public class SysUtils {
     }
 
     private static boolean detectLowEndDevice() {
-        if (CommandLine.isInitialized()) {
-            if (CommandLine.getInstance().hasSwitch(BaseSwitches.LOW_END_DEVICE_MODE)) {
-                int mode = Integer.parseInt(CommandLine.getInstance().getSwitchValue(
-                        BaseSwitches.LOW_END_DEVICE_MODE));
-                if (mode == 1) return true;
-                if (mode == 0) return false;
-            }
+        assert CommandLine.isInitialized();
+        if (CommandLine.getInstance().hasSwitch(BaseSwitches.LOW_END_DEVICE_MODE)) {
+            int mode = Integer.parseInt(CommandLine.getInstance().getSwitchValue(
+                    BaseSwitches.LOW_END_DEVICE_MODE));
+            if (mode == 1) return true;
+            if (mode == 0) return false;
         }
 
         if (Build.VERSION.SDK_INT <= ANDROID_LOW_MEMORY_ANDROID_SDK_THRESHOLD) {

content/public/android/java/src/org/chromium/content/app/ChildProcessService.java

@@ -130,6 +130,14 @@ public class ChildProcessService extends Service {
             @Override
             public void run()  {
                 try {
+                    // CommandLine must be initialized before others, e.g., Linker.isUsed()
+                    // may check the command line options.
+                    synchronized (mMainThread) {
+                        while (mCommandLineParams == null) {
+                            mMainThread.wait();
+                        }
+                    }
+                    CommandLine.init(mCommandLineParams);
                     boolean useLinker = Linker.isUsed();
                     boolean requestedSharedRelro = false;
                     if (useLinker) {
@@ -138,23 +146,16 @@ public class ChildProcessService extends Service {
                                 mMainThread.wait();
                             }
                         }
-                        if (mLinkerParams != null) {
-                            if (mLinkerParams.mWaitForSharedRelro) {
-                                requestedSharedRelro = true;
-                                Linker.initServiceProcess(mLinkerParams.mBaseLoadAddress);
-                            } else {
-                                Linker.disableSharedRelros();
-                            }
-                            Linker.setTestRunnerClassName(mLinkerParams.mTestRunnerClassName);
+                        assert mLinkerParams != null;
+                        if (mLinkerParams.mWaitForSharedRelro) {
+                            requestedSharedRelro = true;
+                            Linker.initServiceProcess(mLinkerParams.mBaseLoadAddress);
+                        } else {
+                            Linker.disableSharedRelros();
                         }
+                        Linker.setTestRunnerClassName(mLinkerParams.mTestRunnerClassName);
                     }
                     boolean isLoaded = false;
-                    synchronized (mMainThread) {
-                        while (mCommandLineParams == null) {
-                            mMainThread.wait();
-                        }
-                    }
-                    CommandLine.init(mCommandLineParams);
                     if (CommandLine.getInstance().hasSwitch(
                             BaseSwitches.RENDERER_WAIT_FOR_JAVA_DEBUGGER)) {
                         android.os.Debug.waitForDebugger();
@@ -254,9 +255,9 @@ public class ChildProcessService extends Service {
         synchronized (mMainThread) {
             mCommandLineParams = intent.getStringArrayExtra(
                     ChildProcessConnection.EXTRA_COMMAND_LINE);
-            mLinkerParams = null;
-            if (Linker.isUsed())
-                mLinkerParams = new ChromiumLinkerParams(intent);
+            // mLinkerParams is never used if Linker.isUsed() returns false.
+            // See onCreate().
+            mLinkerParams = new ChromiumLinkerParams(intent);
             mIsBound = true;
             mMainThread.notifyAll();
         }