Unit Test for WebView animating in and out of screen

android_webview/browser/browser_view_renderer.cc

 // Copyright 2014 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.
 
 #include "android_webview/browser/browser_view_renderer.h"
 
 #include "android_webview/browser/browser_view_renderer_client.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 198 matching lines @@
   if (!hardware_enabled_) {
     TRACE_EVENT0("android_webview", "InitializeHwDraw");
     hardware_enabled_ = compositor_->InitializeHwDraw();
   }
   if (!hardware_enabled_) {
     TRACE_EVENT_INSTANT0("android_webview", "EarlyOut_HardwareNotEnabled",
                          TRACE_EVENT_SCOPE_THREAD);
     return false;
   }
 
+  if (last_on_draw_global_visible_rect_.IsEmpty()) {
+    // WebView could be offscreen. Need to make sure WebView invalidates when
+    // it is animated into the screen again.
+    shared_renderer_state_.SetForceInvalidateOnNextDrawGLOnUI(true);
+  }
+
   ReturnResourceFromParent();
   if (shared_renderer_state_.HasCompositorFrameOnUI()) {
     TRACE_EVENT_INSTANT0("android_webview",
                          "EarlyOut_PreviousFrameUnconsumed",
                          TRACE_EVENT_SCOPE_THREAD);
     DidSkipCompositeInDraw();
     return true;
   }
 
   scoped_ptr<cc::CompositorFrame> frame = CompositeHw();
@@ skipping 555 matching lines @@
   base::StringAppendF(&str,
                       "overscroll_rounding_error_: %s ",
                       overscroll_rounding_error_.ToString().c_str());
   base::StringAppendF(
       &str, "on_new_picture_enable: %d ", on_new_picture_enable_);
   base::StringAppendF(&str, "clear_view: %d ", clear_view_);
   return str;
 }
 
 }  // namespace android_webview