aw: Use correct viewport for hardware draw

Use the webview size, the layer size, and the current matrix to
calculate the current "visible rect". This is the the webview rect
transformed by the matrix and then intersected with the viewport.

This will prevent tile thrashing when the clip is changing wildly.

BUG=

Review URL: https://codereview.chromium.org/227743011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262481 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 15 insertions, 2 deletions

diff --git a/android_webview/browser/browser_view_renderer.cc b/android_webview/browser/browser_view_renderer.cc
index c3d9ecb..937ed13 100644
--- a/android_webview/browser/browser_view_renderer.cc
+++ b/android_webview/browser/browser_view_renderer.cc
@@ -99,6 +99,8 @@ bool BrowserViewRenderer::OnDraw(jobject java_canvas,
   draw_gl_input_.frame_id++;
   draw_gl_input_.scroll_offset = scroll;
   draw_gl_input_.global_visible_rect = global_visible_rect;
+  draw_gl_input_.width = width_;
+  draw_gl_input_.height = height_;
   if (clear_view_)
     return false;
   if (is_hardware_canvas && attached_to_window_) {
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index 59356db..a45da7f 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -15,6 +15,8 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
+#include "ui/gfx/geometry/rect_conversions.h"
+#include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/transform.h"
 
 using content::BrowserThread;
@@ -114,11 +116,18 @@ bool HardwareRenderer::DrawGL(AwDrawGLInfo* draw_info, DrawGLResult* result) {
                       draw_info->clip_right - draw_info->clip_left,
                       draw_info->clip_bottom - draw_info->clip_top);
 
+  gfx::Rect viewport(draw_info->width, draw_info->height);
+  if (!draw_info->is_layer) {
+    gfx::RectF view_rect(input.width, input.height);
+    transform.TransformRect(&view_rect);
+    viewport.Intersect(gfx::ToEnclosingRect(view_rect));
+  }
+
   bool did_draw = shared_renderer_state_->GetCompositor()->
       DemandDrawHw(
           gfx::Size(draw_info->width, draw_info->height),
           transform,
-          clip_rect,  // viewport
+          viewport,
           clip_rect,
           state_restore.stencil_enabled());
   gl_surface_->ResetBackingFrameBufferObject();
diff --git a/android_webview/browser/shared_renderer_state.cc b/android_webview/browser/shared_renderer_state.cc
index ba198a3..fb17afb 100644
--- a/android_webview/browser/shared_renderer_state.cc
+++ b/android_webview/browser/shared_renderer_state.cc
@@ -10,7 +10,7 @@
 
 namespace android_webview {
 
-DrawGLInput::DrawGLInput() : frame_id(0) {}
+DrawGLInput::DrawGLInput() : frame_id(0), width(0), height(0) {}
 
 DrawGLResult::DrawGLResult() : frame_id(0), clip_contains_visible_rect(false) {}
 
diff --git a/android_webview/browser/shared_renderer_state.h b/android_webview/browser/shared_renderer_state.h
index c85552d..a7ec60c 100644
--- a/android_webview/browser/shared_renderer_state.h
+++ b/android_webview/browser/shared_renderer_state.h
@@ -19,6 +19,8 @@ struct DrawGLInput {
   unsigned int frame_id;
   gfx::Rect global_visible_rect;
   gfx::Vector2d scroll_offset;
+  int width;
+  int height;
 
   DrawGLInput();
 };