Replaced is_null() with is_valid in SurfaceId and related classes.

android_webview/browser/hardware_renderer.cc

Index: android_webview/browser/hardware_renderer.cc
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index 9f4cf32646f148f55ae2a39f6e5b000027ff2338..0a453dc3edf26b9463489115e30834aee94a6972 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -41,7 +41,7 @@ HardwareRenderer::HardwareRenderer(RenderThreadManager* state)
 HardwareRenderer::~HardwareRenderer() {
   // Must reset everything before |surface_factory_| to ensure all
   // resources are returned before resetting.
-  if (!child_id_.is_null())
+  if (child_id_.is_valid())
     DestroySurface();
   surface_factory_.reset();
   surfaces_->GetSurfaceManager()->UnregisterSurfaceFactoryClient(
@@ -89,7 +89,7 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
     if (!compositor_id_.Equals(child_frame_->compositor_id) ||
         last_submitted_compositor_frame_sink_id_ !=
             child_frame_->compositor_frame_sink_id) {
-      if (!child_id_.is_null())
+      if (child_id_.is_valid())
         DestroySurface();
 
       // This will return all the resources to the previous compositor.
@@ -109,8 +109,8 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
             ->output_rect.size();
     bool size_changed = frame_size != frame_size_;
     frame_size_ = frame_size;
-    if (child_id_.is_null() || size_changed) {
-      if (!child_id_.is_null())
+    if (!child_id_.is_valid() || size_changed) {
+      if (child_id_.is_valid())
         DestroySurface();
       AllocateSurface();
     }
@@ -135,7 +135,7 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
         draw_constraints);
   }
 
-  if (child_id_.is_null())
+  if (!child_id_.is_valid())
     return;
 
   gfx::Rect clip(draw_info->clip_left, draw_info->clip_top,
@@ -146,7 +146,7 @@ void HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info) {
 }
 
 void HardwareRenderer::AllocateSurface() {
-  DCHECK(child_id_.is_null());
+  DCHECK(!child_id_.is_valid());
   DCHECK(surface_factory_);
   child_id_ = surface_id_allocator_->GenerateId();
   surface_factory_->Create(child_id_);
@@ -154,7 +154,7 @@ void HardwareRenderer::AllocateSurface() {
 }
 
 void HardwareRenderer::DestroySurface() {
-  DCHECK(!child_id_.is_null());
+  DCHECK(child_id_.is_valid());
   DCHECK(surface_factory_);
 
   // Submit an empty frame to force any existing resources to be returned.