aw: Default surface_rect_empty to true

The default for an "is empty" value should be true to better match
reality. This is breaking the case where an offscreen webview is
directly translated on-screen without another onDraw recording on the UI
thread. The comparison in BVR::OnParentDrawConstraintsUpdated is
supposed to catch this case and cause another invalidate.

This CL refers to internal bug b/117560442

Change-Id: Ic03f91631780a2057931cb39cdecd04d32f52b1d
Reviewed-on: https://chromium-review.googlesource.com/c/1295315
Commit-Queue: Bo <boliu@chromium.org>
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604297}

android_webview/browser/browser_view_renderer_unittest.cc

@@ -251,6 +251,70 @@ class TestAnimateInAndOutOfScreen : public RenderingTest {
 
 RENDERING_TEST_F(TestAnimateInAndOutOfScreen);
 
+class TestAnimateOnScreenWithoutOnDraw : public RenderingTest {
+ public:
+  void StartTest() override {
+    browser_view_renderer_->PostInvalidate(ActiveCompositor());
+  }
+
+  void WillOnDraw() override {
+    RenderingTest::WillOnDraw();
+    // Set empty tile viewport on first frame.
+    browser_view_renderer_->PrepareToDraw(gfx::Vector2d(), gfx::Rect());
+  }
+
+  void DidOnDraw(bool success) override {
+    EXPECT_TRUE(success);
+    on_draw_count_++;
+  }
+
+  bool WillDrawOnRT(AwDrawGLInfo* draw_info) override {
+    will_draw_on_rt_count_++;
+    // What happens in practice is draw functor is skipped initially since
+    // it is offscreen so entirely clipped. Then later, the webview is moved
+    // onscreen without another OnDrawon UI thread, and draw functor is called
+    // with non-empty clip. Here in the test we pretend this second draw happens
+    // immediately.
+    bool result = RenderingTest::WillDrawOnRT(draw_info);
+    assertNonEmptyClip(draw_info);
+    return result;
+  }
+
+  void OnParentDrawConstraintsUpdated() override {
+    switch (on_draw_count_) {
+      case 0:
+        // This OnParentDrawConstraintsUpdated is generated by
+        // connecting the compositor frame consumer to the producer.
+        break;
+      case 1:
+        // DrawOnRT skipped for frame 1 so this should not happen.
+        EXPECT_TRUE(window_->on_draw_hardware_pending());
+        EndTest();
+        break;
+      case 2:
+        // Might happen due to invalidate on_draw_hardware_pending from
+        // previous frame.
+        break;
+      default:
+        FAIL();
+        break;
+    }
+  }
+
+ private:
+  void assertNonEmptyClip(AwDrawGLInfo* draw_info) {
+    gfx::Rect clip(draw_info->clip_left, draw_info->clip_top,
+                   draw_info->clip_right - draw_info->clip_left,
+                   draw_info->clip_bottom - draw_info->clip_top);
+    ASSERT_FALSE(clip.IsEmpty());
+  }
+
+  int on_draw_count_ = 0;
+  int will_draw_on_rt_count_ = 0;
+};
+
+RENDERING_TEST_F(TestAnimateOnScreenWithoutOnDraw);
+
 class CompositorNoFrameTest : public RenderingTest {
  public:
   CompositorNoFrameTest() : on_draw_count_(0) {}

android_webview/browser/parent_compositor_draw_constraints.cc

@@ -9,8 +9,7 @@
 namespace android_webview {
 
 ParentCompositorDrawConstraints::ParentCompositorDrawConstraints()
-    : is_layer(false), surface_rect_empty(false) {
-}
+    : is_layer(false), surface_rect_empty(true) {}
 
 ParentCompositorDrawConstraints::ParentCompositorDrawConstraints(
     bool is_layer,

android_webview/browser/test/fake_window.h

@@ -58,6 +58,8 @@ class FakeWindow {
 
   void RequestDrawGL(FakeFunctor* functor);
 
+  bool on_draw_hardware_pending() const { return on_draw_hardware_pending_; }
+
  private:
   class ScopedMakeCurrent;