Disable hardware acceleration for ChromeActivities on low-end devices.

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
index 38f3cb475f0200764e46b93ee6a5591eb43721ad..831aa022ba1be3c9637bf27aef7991f701c103e8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
@@ -10,6 +10,7 @@ import android.app.SearchManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.content.pm.ApplicationInfo;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
 import android.graphics.Color;
@@ -33,6 +34,7 @@ import android.view.ViewStub;
 import android.view.ViewTreeObserver;
 import android.view.ViewTreeObserver.OnPreDrawListener;
 import android.view.Window;
+import android.view.WindowManager;
 import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.AccessibilityManager.AccessibilityStateChangeListener;
 import android.view.accessibility.AccessibilityManager.TouchExplorationStateChangeListener;
@@ -42,6 +44,7 @@ import org.chromium.base.BaseSwitches;
 import org.chromium.base.BuildInfo;
 import org.chromium.base.CommandLine;
 import org.chromium.base.Log;
+import org.chromium.base.SysUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.TraceEvent;
 import org.chromium.base.VisibleForTesting;
@@ -268,6 +271,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
                             .removeOnPreDrawListener(mFirstDrawListener);
                     mFirstDrawListener = null;
                     onFirstDrawComplete();
+                    checkHardwareAcceleration();
                     return true;
                 }
             };
@@ -310,6 +314,8 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
 
         mCompositorViewHolder = (CompositorViewHolder) findViewById(R.id.compositor_view_holder);
         mCompositorViewHolder.setRootView(getWindow().getDecorView().getRootView());
+
+        enableHardwareAcceleration();
     }
 
     /**
@@ -1392,4 +1398,29 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
 
     @Override
     public void onSceneChange(Layout layout) { }
+
+    private void enableHardwareAcceleration() {
+        // HW acceleration is disabled in the manifest. Enable it only on high-end devices.
+        if (!SysUtils.isLowEndDevice()) {
+            getWindow().addFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
+        }
+    }
+
+    private void checkHardwareAcceleration() {

[aelias_OOO_until_Jul13, 2015/07/17 02:48:25]

We generally don't add code that intentionally crashes the browser, that can
backfire in the wild.  We only do so with DCHECK()s that only crash debug
builds.

[DmitrySkiba, 2015/07/17 16:55:14]

This is rough DCHECK alternative for the Java - I check
ApplicationInfo.FLAG_DEBUGGABLE before doing further checks. As I understand
without crbug.com/462676 this closest as we can get. 

+        // Check that HW acceleration is disabled only on low-end devices.
+        if ((getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0) {
+            if (SysUtils.isLowEndDevice()
+                    && getWindow().getDecorView().isHardwareAccelerated()) {
+                throw new AssertionError(String.format(
+                        "%s uses hardware acceleration on the low-end device!",
+                        getClass().getSimpleName()));
+            }
+            if (!SysUtils.isLowEndDevice()
+                    && !getWindow().getDecorView().isHardwareAccelerated()) {
+                throw new AssertionError(String.format(
+                        "%s doesn't use hardware acceleration on the high-end device!",
+                        getClass().getSimpleName()));
+            }
+        }
+    }
 }