[Android] Initialize CommandLine before any usage in Render.

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

Index: base/android/java/src/org/chromium/base/SysUtils.java
diff --git a/base/android/java/src/org/chromium/base/SysUtils.java b/base/android/java/src/org/chromium/base/SysUtils.java
index eabef61c9e18469f7417d9e52c60a0e90773fb03..1c8378c1255dfe7dbe836e1f84e01ac0e1a88864 100644
--- a/base/android/java/src/org/chromium/base/SysUtils.java
+++ b/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();

[nyquist, 2014/10/23 22:30:48]

How does this work for the ChildProcessLauncher?

The static member field
org.chromium.content.browser.ChildProcessLauncher#sBindingManager is statically
initialized though this call hierarchy:
org.chromium.content.browser.BindingManagerImpl#createBindingManager
org.chromium.base.SysUtils#isLowEndDevice
org.chromium.base.SysUtils#detectLowEndDevice

Are we sure that static initializer is never run before the CommandLine has been
initialized?

[Feng Qian, 2014/10/23 22:57:26]

ChildProcessLauncher is called in browser process and CommandLine was
initialized already.

The assert here is to catch and prevent the case isLowEndDevice from being
called but command line wasn't initialized.

The try bot doesn't break tests, so I assume existing code wasn't broken by this
CL, and future violation should be caught by new assertion.


On 2014/10/23 22:30:48, nyquist wrote:

[nyquist, 2014/10/24 18:14:42]

The class is initialized whenever: 
- An instance of ChildProcessLauncher is created.
- A static method declared by ChildProcessLauncher is invoked.
- A static field declared by ChildProcessLauncher is assigned.
- A static field declared by ChildProcessLauncher is used and the field is not a
constant variable.
- An assert statement lexically nested within ChildProcessLauncher is executed.
(from http://docs.oracle.com/javase/specs/jls/se7/html/jls-12.html#jls-12.4)

And then because of the static member in ChildProcessLauncher:
private static BindingManager sBindingManager =
BindingManagerImpl.createBindingManager();
and createBindingManager() calls into SysUtils#isLowEndDevice() ->
SysUtils#detectLowEndDevice(), any code accessing static methods on
ChildProcessLauncher (say warmUp, onSentToBackground, setInForeground,
onBrougtToForeground) would cause a crash in debug builds.

Is that your intention? If it is, then I think that is fine with me. Just wanted
to check.

On 2014/10/23 22:57:26, Feng Qian wrote:

[Feng Qian, 2014/10/27 16:09:16]

Yes, that's intended, we want to catch all cases where detectLowEndDevice is
called but command line wasn't initialized.


On 2014/10/24 18:14:42, nyquist wrote:

+        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) {