Resize only the virtual viewport when the OSK triggers a resize.

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 162d1fa3d260bacf4d5b0edd52bc7e306bf99bb9..002717d4017cbaf4b92c992fa8ecf6a01db6de0c 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
@@ -205,6 +205,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
     private ActivityWindowAndroid mWindowAndroid;
     private ChromeFullscreenManager mFullscreenManager;
     private CompositorViewHolder mCompositorViewHolder;
+    private InsetConsumerView mInsetConsumerView;
     private ContextualSearchManager mContextualSearchManager;
     private ReaderModeManager mReaderModeManager;
     private SnackbarManager mSnackbarManager;
@@ -354,6 +355,26 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
 
         mCompositorViewHolder = (CompositorViewHolder) findViewById(R.id.compositor_view_holder);
         mCompositorViewHolder.setRootView(getWindow().getDecorView().getRootView());
+
+        // Add a custom view right after the root view that consumes the insets
+        // and stores it to access later. ContentViewCore needs the insets to
+        // determine the portion of the screen obscured by non-content

[Ted C, 2016/03/12 00:01:43]

I don't really like mucking with the view hierarchy if we can avoid it.  I
played around with this a bit and you can just do:

mInsetConsumerView = new InsetConsumerView(this);
rootView.addView(mInsetConsumerView, 0);

It needs to be at position 0 because of how insets are consumed.  The first
child of a view that states it has consumed the insets wins.  By adding
ourselves first, we can see them but signal we don't use them.

This does have some implications, but I will mention those in the
InsetConsumerView class.  I think this is much nicer though.

[ymalik, 2016/03/14 22:19:01]

Done.

+        // displaying things such as the OSK.
+        ViewGroup rootView = (ViewGroup) getWindow().getDecorView().getRootView();

[Ted C, 2016/03/12 00:01:43]

this is also needed above in setRootView, so let's pull it out as a shared var.

[ymalik, 2016/03/14 22:19:01]

Done.

+        // Setting fitsSystemWindows to false ensures that the root view
+        // doesn't consume the insets.
+        rootView.setFitsSystemWindows(false);

[Ted C, 2016/03/12 00:01:43]

this didn't seem necessary in my prototyping

[ymalik, 2016/03/14 22:19:01]

I had this in case the compat lib was ever changed and the root view did
actually consume the insets. I can get rid of this if this is not a legitimate
concern. WDYT?

+        // Transfer child view hierarchy to InsetConsumerView. This is needed to
+        // ensure that the insets are applied properly.
+        InsetConsumerView insetConsumerView = new InsetConsumerView(this);
+        insetConsumerView.setFitsSystemWindows(true);

[Ted C, 2016/03/12 00:01:44]

move this to the constructor

[ymalik, 2016/03/14 22:19:01]

I don't think we need this with the sibling approach (since we're not actually
consuming the insets)

+        while (rootView.getChildCount() > 0) {
+            View currentChild = rootView.getChildAt(0);
+            rootView.removeView(currentChild);
+            insetConsumerView.addView(currentChild);
+        }
+        rootView.addView(insetConsumerView);
+        mInsetConsumerView = insetConsumerView;
     }
 
     /**
@@ -1059,6 +1080,15 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
         return mTabModelSelector;
     }
 
+    /**
+     * Returns the {@link InsetConsumerView} that has the current system window
+     * insets information.
+     * @return The {@link InsetConsumerView}, possibly null.
+     */
+    public InsetConsumerView getInsetConsumerView() {
+        return mInsetConsumerView;
+    }
+
     @Override
     public TabCreatorManager.TabCreator getTabCreator(boolean incognito) {
         return incognito ? mIncognitoTabCreator : mRegularTabCreator;