Use a scrollable tab strip on tablets at small widths

chrome/browser/android/compositor/scene_layer/tab_strip_scene_layer.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TAB_STRIP_SCENE_LAYER_H_
 #define CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TAB_STRIP_SCENE_LAYER_H_
 
 #include <vector>
 
 #include "base/android/jni_android.h"
@@ skipping 23 matching lines @@
   ~TabStripSceneLayer() override;
 
   void SetContentTree(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& jobj,
       const base::android::JavaParamRef<jobject>& jcontent_tree);
 
   void BeginBuildingFrame(JNIEnv* env,
                           const base::android::JavaParamRef<jobject>& jobj,
                           jboolean visible);
+
   void FinishBuildingFrame(JNIEnv* env,
                            const base::android::JavaParamRef<jobject>& jobj);
 
   void UpdateTabStripLayer(JNIEnv* env,
                            const base::android::JavaParamRef<jobject>& jobj,
                            jfloat width,
                            jfloat height,
                            jfloat y_offset,
                            jfloat background_tab_brightness,
                            jfloat brightness,
                            jboolean should_readd_background);
+
   void UpdateNewTabButton(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& jobj,
       jint resource_id,
       jfloat x,
       jfloat y,
       jfloat width,
       jfloat height,
       jboolean visible,
       const base::android::JavaParamRef<jobject>& jresource_manager);
+
   void UpdateModelSelectorButton(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& jobj,
       jint resource_id,
       jfloat x,
       jfloat y,
       jfloat width,
       jfloat height,
       jboolean incognito,
       jboolean visible,
       const base::android::JavaParamRef<jobject>& jresource_manager);
+
+  void UpdateTabStripLeftFade(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& jobj,
+      jint resource_id,
+      jfloat opacity,
+      const base::android::JavaParamRef<jobject>& jresource_manager);
+
+  void UpdateTabStripRightFade(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& jobj,
+      jint resource_id,
+      jfloat opacity,
+      const base::android::JavaParamRef<jobject>& jresource_manager);
+
   void PutStripTabLayer(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& jobj,
       jint id,
       jint close_resource_id,
       jint handle_resource_id,
       jboolean foreground,
       jboolean close_pressed,
       jfloat toolbar_width,
       jfloat x,
       jfloat y,
       jfloat width,
       jfloat height,
       jfloat content_offset_x,
       jfloat close_button_alpha,
       jboolean is_loading,
       jfloat spinner_rotation,
       jfloat border_opacity,
       const base::android::JavaParamRef<jobject>& jlayer_title_cache,
       const base::android::JavaParamRef<jobject>& jresource_manager);
 
  private:
   scoped_refptr<TabHandleLayer> GetNextLayer(
       LayerTitleCache* layer_title_cache);
 
   typedef std::vector<scoped_refptr<TabHandleLayer>> TabHandleLayerList;
 
   scoped_refptr<cc::SolidColorLayer> tab_strip_layer_;
+  scoped_refptr<cc::Layer> scrollable_strip_layer_;
   scoped_refptr<cc::UIResourceLayer> new_tab_button_;
+  scoped_refptr<cc::UIResourceLayer> left_fade_;
+  scoped_refptr<cc::UIResourceLayer> right_fade_;
   scoped_refptr<cc::UIResourceLayer> model_selector_button_;
 
   float background_tab_brightness_;
   float brightness_;
   unsigned write_index_;
   TabHandleLayerList tab_handle_layers_;
   SceneLayer* content_tree_;
 
   DISALLOW_COPY_AND_ASSIGN(TabStripSceneLayer);
 };
 
 bool RegisterTabStripSceneLayer(JNIEnv* env);
 
 }  // namespace android
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_ANDROID_COMPOSITOR_SCENE_LAYER_TAB_STRIP_SCENE_LAYER_H_