Adding Launcher3 callbacks for trimming memory.

It will help reduce memory footprint of Launcher, when in background.
It is required to help deallocate images, when Google Now Launcher
goes into the background. See cl/83222937/ .

Plan after this CL:
- Generate drop CL with launcher3_drop.sh. Add empty metods to
 make code compile.
- Sync the cl/83222937 and hide the code behind the feature flag.

It was previously submitted in ag/628070 and reverted in ag/630423
due to GSA release schedule.

Change-Id: I56eee618b86d518d0afc362b6cf44c3bbec1f19c

3 files changed, 8 insertions, 0 deletions

diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index cd2bc596a..0414a5b1e 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -3823,6 +3823,9 @@ public class Launcher extends Activity
                 mAppsCustomizeTabHost.trimMemory();
             }
         }
+        if (mLauncherCallbacks != null) {
+            mLauncherCallbacks.onTrimMemory(level);
+        }
     }
 
     protected void showWorkspace(boolean animated) {
diff --git a/src/com/android/launcher3/LauncherCallbacks.java b/src/com/android/launcher3/LauncherCallbacks.java
index a1f4e0b90..d8128d6e5 100644
--- a/src/com/android/launcher3/LauncherCallbacks.java
+++ b/src/com/android/launcher3/LauncherCallbacks.java
@@ -42,6 +42,7 @@ public interface LauncherCallbacks {
     public void dump(String prefix, FileDescriptor fd, PrintWriter w, String[] args);
     public void onHomeIntent();
     public boolean handleBackPressed();
+    public void onTrimMemory(int level);
 
     /*
      * Extension points for providing custom behavior on certain user interactions.
diff --git a/src/com/android/launcher3/LauncherExtension.java b/src/com/android/launcher3/LauncherExtension.java
index b264042cf..fe9bd6c23 100644
--- a/src/com/android/launcher3/LauncherExtension.java
+++ b/src/com/android/launcher3/LauncherExtension.java
@@ -108,6 +108,10 @@ public class LauncherExtension extends Launcher {
         }
 
         @Override
+        public void onTrimMemory(int level) {
+        }
+
+        @Override
         public void onLauncherProviderChange() {
         }