[Android WebView] OnMemoryPressure to drop tile memory

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index f0f286ffb8adcaf325ccd72bb5cb971b6c1d55ae..ab8700ae06a0b844851b85c355aef5cd173ca82d 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -4,6 +4,8 @@
 
 package org.chromium.android_webview;
 
+import android.content.ComponentCallbacks2;
+import android.content.Context;
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
@@ -523,6 +525,23 @@ public class AwContents {
 
         onVisibilityChanged(mContainerView, mContainerView.getVisibility());
         onWindowVisibilityChanged(mContainerView.getWindowVisibility());
+
+        containerView.getContext().registerComponentCallbacks(

[joth, 2013/10/02 10:47:01]

could you move this up to line 520? onVisibilityChanged() onwards is potentially
moving to a new method.

declaring the innerclass out of line would keep this c'tor a bit more readable.
(see IoThreadClientImpl etc. maybe group with this on those lines at top of
method)

[boliu, 2013/10/02 14:09:55]

This moved to attach/detach since we need to explicitly call unregister as well.
Done

+            new ComponentCallbacks2() {
+                  @Override
+                  public void onTrimMemory(int level) {
+                      if (mNativeAwContents == 0) return;
+                      nativeTrimMemory(mNativeAwContents, level);
+                  }
+
+                  @Override
+                  public void onLowMemory() {
+                  }
+
+                  @Override
+                  public void onConfigurationChanged(Configuration configuration) {
+                  }
+            });
     }
 
     /**
@@ -1967,4 +1986,6 @@ public class AwContents {
             int nativeAwContents, boolean value, String requestingFrame);
 
     private native void nativeSetJsOnlineProperty(int nativeAwContents, boolean networkUp);
+
+    private native void nativeTrimMemory(int nativeAwContents, int level);
 }