diff -r 000000000000 -r 6474c204b198 mobile/android/base/toolbar/ShapedButton.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/toolbar/ShapedButton.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,146 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.toolbar;
+
+import org.mozilla.gecko.GeckoApplication;
+import org.mozilla.gecko.LightweightTheme;
+import org.mozilla.gecko.LightweightThemeDrawable;
+import org.mozilla.gecko.R;
+import org.mozilla.gecko.widget.ThemedImageButton;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Path;
+import android.graphics.PorterDuff.Mode;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.StateListDrawable;
+import android.util.AttributeSet;
+
+public class ShapedButton extends ThemedImageButton
+                          implements CanvasDelegate.DrawManager {
+    protected final LightweightTheme mTheme;
+
+    private final Path mPath;
+    private final CurveTowards mSide;
+
+    protected final CanvasDelegate mCanvasDelegate;
+
+    private enum CurveTowards { NONE, LEFT, RIGHT };
+
+    public ShapedButton(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mTheme = ((GeckoApplication) context.getApplicationContext()).getLightweightTheme();
+
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.BrowserToolbarCurve);
+        int curveTowards = a.getInt(R.styleable.BrowserToolbarCurve_curveTowards, 0x00);
+        a.recycle();
+
+        if (curveTowards == 0x00)
+            mSide = CurveTowards.NONE;
+        else if (curveTowards == 0x01)
+            mSide = CurveTowards.LEFT;
+        else
+            mSide = CurveTowards.RIGHT;
+
+        // Path is clipped.
+        mPath = new Path();
+        mCanvasDelegate = new CanvasDelegate(this, Mode.DST_IN);
+
+        setWillNotDraw(false);
+    }
+
+    @Override
+    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        if (mSide == CurveTowards.NONE)
+            return;
+
+        final int width = getMeasuredWidth();
+        final int height = getMeasuredHeight();
+        final int curve = (int) (height * 1.125f);
+
+        mPath.reset();
+
+        if (mSide == CurveTowards.RIGHT) {
+            mPath.moveTo(0, 0);
+            mPath.cubicTo(curve * 0.75f, 0,
+                          curve * 0.25f, height,
+                          curve, height);
+            mPath.lineTo(width, height);
+            mPath.lineTo(width, 0);
+            mPath.lineTo(0, 0);
+        } else if (mSide == CurveTowards.LEFT) {
+            mPath.moveTo(width, 0);
+            mPath.cubicTo((width - (curve * 0.75f)), 0,
+                          (width - (curve * 0.25f)), height,
+                          (width - curve), height);
+            mPath.lineTo(0, height);
+            mPath.lineTo(0, 0);
+        }
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        if (mCanvasDelegate != null && mSide != CurveTowards.NONE)
+            mCanvasDelegate.draw(canvas, mPath, getWidth(), getHeight());
+        else
+            defaultDraw(canvas);
+    }
+
+    @Override
+    public void defaultDraw(Canvas canvas) {
+        super.draw(canvas);
+    }
+
+    // The drawable is constructed as per @drawable/shaped_button.
+    @Override
+    public void onLightweightThemeChanged() {
+        final int background = getResources().getColor(R.color.background_tabs);
+        final LightweightThemeDrawable lightWeight = mTheme.getColorDrawable(this, background);
+
+        if (lightWeight == null)
+            return;
+
+        lightWeight.setAlpha(34, 34);
+
+        final StateListDrawable stateList = new StateListDrawable();
+        stateList.addState(PRESSED_ENABLED_STATE_SET, getColorDrawable(R.color.highlight_shaped));
+        stateList.addState(FOCUSED_STATE_SET, getColorDrawable(R.color.highlight_shaped_focused));
+        stateList.addState(PRIVATE_STATE_SET, getColorDrawable(R.color.background_tabs));
+        stateList.addState(EMPTY_STATE_SET, lightWeight);
+
+        setBackgroundDrawable(stateList);
+    }
+
+    @Override
+    public void onLightweightThemeReset() {
+        setBackgroundResource(R.drawable.shaped_button);
+    }
+
+    @Override
+    public void setBackgroundDrawable(Drawable drawable) {
+        if (getBackground() == null || drawable == null) {
+            super.setBackgroundDrawable(drawable);
+            return;
+        }
+
+        int[] padding =  new int[] { getPaddingLeft(),
+                                     getPaddingTop(),
+                                     getPaddingRight(),
+                                     getPaddingBottom()
+                                   };
+        drawable.setLevel(getBackground().getLevel());
+        super.setBackgroundDrawable(drawable);
+
+        setPadding(padding[0], padding[1], padding[2], padding[3]);
+    }
+
+    @Override
+    public void setBackgroundResource(int resId) {
+        setBackgroundDrawable(getResources().getDrawable(resId));
+    }
+}