Temporarily disable mip generation to investigate mem regression

This patch may have been leading to regressions in memory on Windows.
Temporarily disabling mip map generation to test whether this is the
culprit.

R=khushalsagar

Bug: 867468
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I74467e2f620ecb15af86a6a82c6b772d03c739d1
Reviewed-on: https://chromium-review.googlesource.com/1157273Reviewed-by: Khushal <khushalsagar@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579657}

cc/tiles/gpu_image_decode_cache.cc

@@ -16,6 +16,7 @@
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
+#include "build/build_config.h"
 #include "cc/base/devtools_instrumentation.h"
 #include "cc/base/histograms.h"
 #include "cc/paint/image_transfer_cache_entry.h"
@@ -129,6 +130,12 @@ gfx::Size CalculateSizeForMipLevel(const DrawImage& draw_image,
 // Determines whether a draw image requires mips.
 bool ShouldGenerateMips(const DrawImage& draw_image,
                         int upload_scale_mip_level) {
+#if defined(OS_WIN)
+  // TODO(ericrk): Temporarily disable to investigate memory regression on
+  // Windows. https://crbug.com/867468
+  return false;
+#endif  // defined(OS_WIN)
+
   // If filter quality is less than medium, don't generate mips.
   if (draw_image.filter_quality() < kMedium_SkFilterQuality)
     return false;

cc/tiles/gpu_image_decode_cache_unittest.cc

@@ -6,6 +6,7 @@
 
 #include <memory>
 
+#include "build/build_config.h"
 #include "cc/paint/draw_image.h"
 #include "cc/paint/image_transfer_cache_entry.h"
 #include "cc/paint/paint_image_builder.h"
@@ -2475,6 +2476,12 @@ TEST_P(GpuImageDecodeCacheTest, DecodeToScaleNoneQuality) {
 }
 
 TEST_P(GpuImageDecodeCacheTest, BasicMips) {
+#if defined(OS_WIN)
+  // TODO(ericrk): Mips are temporarily disabled to investigate a memory
+  // regression on Windows. https://crbug.com/867468
+  return;
+#endif  // defined(OS_WIN)
+
   auto decode_and_check_mips = [this](SkFilterQuality filter_quality,
                                       SkSize scale, gfx::ColorSpace color_space,
                                       bool should_have_mips) {
@@ -2534,6 +2541,12 @@ TEST_P(GpuImageDecodeCacheTest, BasicMips) {
 }
 
 TEST_P(GpuImageDecodeCacheTest, MipsAddedSubsequentDraw) {
+#if defined(OS_WIN)
+  // TODO(ericrk): Mips are temporarily disabled to investigate a memory
+  // regression on Windows. https://crbug.com/867468
+  return;
+#endif  // defined(OS_WIN)
+
   auto cache = CreateCache();
   bool is_decomposable = true;
   auto filter_quality = kMedium_SkFilterQuality;